Pediatric Hip Disorders Flashcards
Developmental Dysplasia of the Hip (DDH)
general
Spectrum of disorders of the hip joint (acetabulum and proximal femur) characterized by hip instability and resulting in subluxation or dislocation
Subluxation: partial loss of contact
Dislocation: total loss of contact
Mostly presents during the first few months of life
Often first recognized due to hip laxity on newborn exam
Epidemiology
More common in children of Caucasian descent
80% of cases are girls
~60% of cases are unilateral, with the left hip most commonly affected due to intrauterine positioning
DDH
RF
Breech position, especially in late pregnancy (≥ 34 weeks gestation)
Frank breech presentation with both knees extended poses the highest risk
The American Academy of Pediatrics recommends ultrasound DDH screening of all female breech babies
Femalesex (4x increase)
Due to circulating female hormones produced by the fetus → ligamentous laxity
Family historyof DDH
Tight lower-extremity swaddling in the adducted and extended position
DDH
Patho
Normal development of the hip is dependent on contact between the acetabulum and femoral head
In DDH:
There is interrupted contact between the femoral head and acetabulum
The femoral head gives depth to the acetabulum during normal fetal development and interrupted contact causes the acetabulum to become shallow
A shallow acetabulum results in decreased coverage of the femoral head, which results in hip instability
DDH
Clin man
Depends on the child’s age and the severity of the pathology
Shows a progression through time, manifesting differently and more severely as time passes
Routine hip evaluation should be performed at all well-child exams until 9 months of age
Symptoms
Hips make a popping or clicking sound
Leg length discrepancy
Hip flexibility discrepancy (limited abduction)
Uneven skin folds of the thigh and/or buttocks
Limp with ambulation
DDH
Diagnosis - Neonates aged 0–2 months
Barlow maneuver
(dislocation of hips at rest)
Steps:
Child is placed in the supine position on a stable surface
Examiner grasps the child’s thighs with the thumb and index finger
The child’s hips are adducted while applying a posterior force
Positive when the femoral head is felt slipping, posteriorly, out of the acetabulum - a “palpable clunk” orsubluxation may be felt on positive exams
DDH
Diagnosis - Neonates aged 0–2 months
Ortolani maneuver
(reduction of hips at rest)
Steps:
Child is placed in the supine position on a stable surface
Examiner grasps the child’sthigh with the thumb and index finger
From an adducted position, the child’s hip is abducted while the trochanter is pushed anteriorly
Positive when a “hip clunk” is felt or if the maneuver reduces the hip (sound or sensation of the femoral head slipping back into the acetabulum)
DDH
Diagnosis - Children 2–3 months old
Galeazzi test
Child lays supine with hips flexed to 45° and knees flexed to 90°
Child’s feet are placed flat and level on a surface beside each other
Positive if one knee appears lower than the other
Occurs because thehead of the femuris displaced posteriorly, shortening the length of thethigh
A positive test indicates a lowerleg–length discrepancyand is not specific to DDH
DDH
Diagnosis - Children 2–3 months old
Klisic test
Examiner places a finger on the greater trochanter and a finger of the same handon the anterior-superior iliacspine
A line is drawn through the tips of both fingers
If the line passes through or above the umbilicus, the hip is adequately reduced (normal hip exam)
If the line is below the umbilicus, the test is positive for a displaced hip (positive result)
DDH
Diagnosis – Ambulatory Children
Trendelenburg sign
Patient is unable to maintain their pelvisin line horizontally while standing on the ipsilateralleg
Indicates hip abductor weakness of the standing leg
DDH
imaging
Used to confirm the diagnosis:
In children with risk factors and a normal physical examination
In children with inconclusive physical examination findings
Hip ultrasound:
Useful as an adjunct to the physical exam until 4–6 months of age
HipX-ray:
Used from 4–6 months of age when the acetabulum and femoral head begin to ossify
Head of the femur should be inferior to the Hilgenreiner’s line (H line)
DDH
0-6mo Tx
The earlier the treatment, the better theprognosis
Goals:
Obtaining and maintaining concentric reduction of thehead of the femurin the acetabulum
Avoiding complications, notablyavascularnecrosis
Newborns 0–4 weeks of age
Mild instability without dislocation of the hip can be watched (90% resolve spontaneously)
Referral to an orthopedic surgeon if the hips are dislocatable
Infants 4 weeks to 6 months of age
Pavlik harness is most often utilized
Treatment for 2–3 months, until a physical exam or ultrasound demonstrates hip stability
DDH
6mo-6y Tx
Infants between the ages of 6 months and 2 years
Initially, a closed reduction is attempted
If unsuccessful, an open reduction may be required
For both operations, a spica cast is used post-operatively
Children from 2–6 years of age
Open reductions are generally required
DDH
complications
Most important complication:avascularnecrosisof the femoralepiphysis(orthopedic emergency!)
Osteoarthritis(OA):
Patientswith DDH are at an increased risk of developing OA
Pain
Abnormalgait
Reduced mobility
Redislocation
Residual subluxation
Slipped Capital Femoral Epiphysis (SCFE)
general and RF
Orthopedic disorder characterized by the pathologic “slipping” or displacement of the femoral head (epiphysis) on the femoral neck
Considered a Salter-Harris type I growth plate fracture because it is a transverse fracture through the growth plate
Epidemiology
Most common hip pathology in pre-adolescents and adolescents
Boys > Girls
Mean age at presentation 12-13 years
Risk factors: obesity, periods of rapid growth, radiation therapy to the hip
Slipped Capital Femoral Epiphysis (SCFE)
Pathophysiology
Slippage progression
Combination of biochemical factors and mechanical factors
Repetitive shear forces applied to a weakened epiphysis →fractureand slipping
Slippage progresses
Metaphysis translates anteriorly and superiorly while rotating externally
Epiphysis remains in the acetabulum
Slipped Capital Femoral Epiphysis (SCFE)
PE
Limpinggait or complete inability to walk in severe cases
Externalrotationof the affectedleg
Drehmann sign: external rotation with passive hip flexion to 90 degrees
Limited internal rotation
Leg-length discrepancyof lower limbs(affected limb is shorter)
Gaitbecomes antalgic as slippage progresses
Slipped Capital Femoral Epiphysis (SCFE)
Dx
Made by a combination of history, physical examination, and plain filmx-rays
HipX-rays (anteroposterior (AP) and frogleglateral views of both hips):
LateralX-ray
Primary way to identify a subtle slip
Epiphysiolysis:growth plate widening or lucency; early radiographic sign
Klein’s line:
In AP view, a line drawn along the superior border of the femoralneckwill intersect less of the femoral head in a child with SCFE;asymmetry between sides
Ifx-raysare normal, but SCFE suspicion remains high, an MRI can demonstrate widening of the growth plate with surroundingedema
Slipped Capital Femoral Epiphysis (SCFE)
management
Immediately non–weight bearing to prevent further slippage
Operative management for stable and unstable cases:
Percutaneous screw fixation through the femoralneck, engaging the epiphysis
Reduction of slippedepiphysisis not recommended because of increased risk ofavascularnecrosis
Prophylactic pinning of the contralateral hip is controversial
Slipped Capital Femoral Epiphysis (SCFE)
Legg Calve Perthes Disease
general
Also known as coxa plana
Disorder of the hip in which blood supply to the proximal femoralepiphysisis temporarily interrupted, resulting in avascular necrosisand permanent deformity of the femoral head and acetabulum
Epidemiology
Boys > Girls
Peak incidence 4-8 years
Unilateral > Bilateral
Risk factors: genetics (10% familial), clotting disorders, trauma, steroid use, developmental dysplasia of the hip
Legg Calve Perthes Disease
Patho
Necrosis
Disruption of blood supply leads tonecrosisof subchondral cortical bone or infarction of femoral capitalepiphysis; infarcted bone softens and dies
Fragmentation
Infarctedbone is reabsorbed
Reossification
Osteoblastic activity becomes prominent and the femoral epiphysis reestablishes
Remodeling
Femoral head reshapes during patient growth; may be enlarged or flattened
Legg Calve Perthes Disease
Clinical findings
Examination ofgait
Antalgic gait: short stance phase due topainwhen loading affected hip
Trendelenburggait: downward tilt ofpelviscontralateral to affected hip during swing phase of walking
Lower extremity exam
Leg-length discrepancy (affectedlegis shorter)
Atrophyof quadriceps/buttocks muscles from disuse
Reducedrange of motionofhip joint (decreased internal rotation and abduction)
Legg Calve Perthes Disease
Imaging
Hip x-rays: anteroposterior (AP) and frog-leg lateral views
Looking for a pathological deformation of hip
Early findings: widening of joint space
Caffey’s sign or crescent sign
Subchondral radiolucent fractureline parallel to articular surface of femoral head
Later findings:
Fragmentationof femoral ossification center
Lateral subluxationand flattening of femoral head
Legg Calve Perthes Disease
Tx
Conservative management
Minimal weight bearing and protection of joint untilossificationis complete:
Hip held inabduction by abduction casts or ambulatory braces
Goal is to promote containment of femoral head within acetabulum
Physical therapyand stretchingexercises to maintain range of motion and muscle tone
Nonsteroidal anti-inflammatory drugs (NSAIDs) if needed forpain management
Children < 6–8 years old have more favorable outcomes to conservative therapy
Surgical therapy
Operative procedures include varus femoral osteotomy and Salter osteotomy (goal is containment of femoral head)
More commonly used in patient > 8 years of age
