Dr. Kevin Yip

Dr Kevin Yip
Orthopaedic Surgeon
MBBS(UK), FRCS(EDIN), FAM(SING), FHKCOS(ORTHO)

Featured on Channel NewsAsia

Hip Examination in the Child

Basics
Description
  • Because many pediatric hip disorders develop only in certain age groups, it is important that the clinician, when performing a hip examination, keep in mind the child’s age and have an understanding of the following age-specific pediatric hip disorders:
    • DDH:
      • Spectrum of conditions resulting in an unstable fit between the femoral head and acetabulum
      • Most cases are detectable at birth by performing the Ortolani and Barlow maneuvers.
      • If not seen at birth, it is usually found when the pediatrician notes asymmetrical abduction or parents notice limp or abnormal gait.
      • Risk factors include: Breech delivery, oligohydramnios, female gender (Male:Female ratio, 1:4), 1st born, positive family history or ethnic background (e.g., Native American).
    • Septic arthritis:
      • Pyogenic infection of the hip
      • Most cases occur before the age of 5 years.
      • Patient is acutely ill and nonweightbearing.
    • Legg-Calve-Perthes syndrome
      • Idiopathic AVN of the femoral head in children
      • Occurs most commonly at age 4-8 years (range, 2-12 years)
      • 90% unilateral
      • Male:Female ratio, 4-5:1.
      • Typical presentation is the insidious onset of a limp that is worsened by activity.
    • Transient synovitis:
      • Self-limited, idiopathic inflammation of the hip joint
      • Most common cause of hip pain in children
      • Occurs most commonly in children 5-6 years old (range, 3-8 years)
      • 95% unilateral
      • Male:Female ratio, 2:1
      • Presents as an acute onset painful limp
    • SCFE:
      • Displacement of the upper femoral epiphysis from the metaphysis through the physeal plate
      • Age at onset: 9-14 years in girls and 10-16 years in boys
      • Male:Female ratio, 1.4-2:1
      • More prevalent in the obese
      • Typical presentation is the insidious onset of pain and limp exacerbated by activity.
Diagnosis
Signs and Symptoms
History
  • Onset of pain:
    • Acute: Fracture, septic arthritis, transient synovitis, osteomyelitis
    • Chronic: Legg-Calve-Perthes syndrome, SCFE, idiopathic chondrolysis of the hip
    • Associated with activity: Legg-Calve-Perthes syndrome, SCFE
    • Location: Hip pain can be referred to the medial thigh and knee.
  • Limp:
    • Acute: Transient synovitis, septic arthritis
    • Chronic: DDH, Legg-Calve-Perthes syndrome, SCFE, developmental coxa vara, idiopathic chondrolysis of the hip, limb-length discrepancy
  • Nonweightbearing:
    • Fracture
    • Septic arthritis
    • Transient synovitis
    • Osteomyelitis
  • Constitutional symptoms:
    • Septic arthritis
    • Osteomyelitis
  • Snapping sound: Iliopsoas snapping hip
Physical Exam: Preambulatory Infants
  • General notes:
    • An upset or crying infant may tighten these muscles, decreasing the value of the examination.
    • To help relax the baby, the family should be allowed to feed or soothe the infant.
  • Inspection and palpation:
    • Excess thigh folds on 1 side may indicate a limb-length discrepancy.
  • Tests and measurements:
    • Ortolani and Barlow maneuvers detect hip instability in newborns <3 months old.
      • After ~3 months, capsule laxity decreases and muscle tightness increases so that the hip cannot be relocated by the Ortolani maneuver.
    • Ortolani maneuver: A sign of entry as the femoral head reduces into the acetabulum:
      • With the baby supine and the knees fully flexed, flex the hips to a right angle and place the long finger of each hand laterally along the axis of the femur over the greater trochanter.
      • Place the thumb of each hand on the inner side of the thigh opposite the lesser trochanter.
      • Lift the thighs into midabduction and exert forward pressure behind the greater trochanter, using the middle finger on 1 side, while the other hand holds the opposite femur and pelvis steady.
      • If the femoral head clunks or slides forward into the acetabulum, the hip has been relocated into the acetabulum.
    • Barlow maneuver: A sign of exit as the femoral head subluxates or dislocates from the acetabulum:
      • With fingers in the same position as for the Ortolani maneuver, exert backward and outward pressure with the thumb on the inner side of the thigh as the hip is adducted.
      • If the femoral head clunks or slips out over the posterior lip of the acetabulum the hip is unstable.
  • Galeazzi (Allis) sign: Indicates limb-length discrepancy, which can be secondary to a unilateral hip problem:
    • With the baby supine on a firm table, flex the knees and hips and put the feet flat on the table.
    • The knee on the side of the shorter limb will be lower than the knee of the normal limb.
  • ROM:
    • Abduction and adduction:
      • With the baby supine on a firm table, flex the knees and hips to 90°.
      • Abduct the legs (average, 78°)
    • Flexion and internal and external rotation:
      • Extension should be 0-20°
      • Average flexion: 140°
      • Average internal/external rotation: 58-80°
Physical Exam: Ambulatory Children
  • The child’s capacity to walk and to understand and follow instructions allows for a broader hip examination than in the preambulatory infant, which provides information on strength, balance, stability, and pain.
  • Standing examination:
    • Measure pelvic tilt.
      • Place hands on the patient’s iliac crests.
      • Any difference in level represents a pelvic tilt and may indicate a limb-length discrepancy
    • Trendelenburg test:
      • Ask the patient to stand on 1 leg.
      • Any contralateral pelvic tilting is a positive Trendelenburg test, which indicates weak abductors or an irritable hip.
  • Gait examination:
    • Observe from in front of and behind the patient.
    • For younger children, ask parents to walk the child down the hall and back.
    • Note any asymmetries (e.g., stride lengths, duration of stance or swing phases).
    • Pathologic gaits:
      • Antalgic (painful) gait: Short strides and a shortened stance phase on the painful side
      • Trendelenburg gait: Swaying or bending of the trunk over the affected hip because the patient shifts the center of gravity to compensate for weak hip abductors or to decrease the joint reactive forces that irritate the affected hip
      • Gluteus maximus gait: Lurching backward during the stance phase of the involved side, which shifts the center of gravity posteriorly to compensate for weak hip extensors.
      • Limb-length discrepancy gait: Abnormal up-and-down motion because the patient with a true limb-length discrepancy of >2 cm bends the longer leg excessively or stands on the toes of the shorter leg.
  • Positioning and leg lengths:
    • With the patient supine, inspect the leg position for symmetric rotation, flexion, and adduction.
    • With the patient supine, measure from the inferior edge of the anterior superior iliac spine to the inferior edge of the ipsilateral medial malleolus.
  • Isolating hip pathology:
    • Roll test:
      • With the patient supine, gently roll the leg internally and externally.
      • Guarding or stiffness on 1 side indicates hip abnormality.
  • ROM:
    • Flexion (average: 120-130°):
      • With the patient lying supine and the knee fully flexed, place 1 hand on the contralateral pelvis.
      • Flex the hip until movement in the contralateral pelvis is noted.
      • The angle between the femur and examining table is the hip flexion.
    • Internal and external rotation:
      • With the patient in the prone position, flex the knees to 90°.
      • Rotate the legs outward for internal rotation and inward for external rotation.
      • The angle between each leg and the line perpendicular to the tabletop is the degree of rotation.
      • Normal internal rotation: Average, 45-50° (range, 20-70°)
      • Normal external rotation: Average, 40° (range, 25-60°)
    • Abduction (average, 40-50°):
      • With the patient lying supine and hip in extension, place 1 finger on the contralateral anterior superior iliac spine.
      • Abduct the hip until the finger feels the pelvis start to tilt.
  • Flexion contracture:
    • Thomas test (normal, 0°):
      • With the patient lying supine, maximally flex both hips.
      • Allow the femur on the ipsilateral side to fall into as much extension as possible, while holding the other hip up.
      • The angle between the femur and examining table is the residual flexion and represents the flexion contracture.
    • Staheli test (normal: 0°):
      • Particularly suitable for the spastic patient
      • The patient is positioned prone, providing a way to flatten the lumbar spine and level the pelvis.
      • Have the patient lie in the prone position with the hip flexed over the end of the table.
      • 1 hip remains flexed at 90°.
      • Gradually extend the other hip while palpating the ipsilateral pelvis.
      • As soon as pelvic motion is detected, measure the amount of residual hip flexion, which represents the flexion contracture.
      • Normal values in the infant: Birth, 21°; 3 months, 11°; <6 months: 3°
  • Muscle strength:
    • Hip flexors (iliopsoas supplied by L1-L3):
      • Have patient sit with knees flexed to 90°.
      • Push against the anterior aspect of the thigh while the patient flexes 1 hip.
    • Hip extensors (gluteus maximus supplied by S1):
      • With the patient in the prone position, push against the posterior thigh while the patient elevates the femur off the table.
    • Hip abductors (gluteus medius and minimus supplied by L5):
      • Have the patient lie on 1 side.
      • Push against the lateral knee of the top leg while the patient elevates it.
    • Hip adductors (adductors longus, brevis, and magnus, gracilis and pectineus supplied by L2-L4):
      • With the patient lying supine, push against the medial aspect of 1 thigh while the patient pushes that leg toward the midline.
Tests
Imaging
  • AP radiographs of the pelvis and/or AP and frog-lateral radiographs of the hip usually are sufficient for diagnosing many common pediatric hip disorders.
  • If plain films are normal, an MRI, CT, or bone scan may be helpful.
  • Common pediatric hip disorders and the imaging modalities that contribute to their diagnoses:
    • Hip fracture or dislocation:
      • AP pelvis/hip radiographs may show upward and lateral displacement of the femoral shaft.
      • In newborns, ultrasound may be helpful in showing a dislocation.
    • DDH:
      • The physical examination usually is sufficient for diagnosing and initiating treatment.
      • Radiographs of the hip in neonates are difficult to interpret because the femoral head is cartilaginous.
      • Ultrasound can show an unstable or dislocated hip joint, and is particularly useful before the femoral head has ossified.
    • Septic arthritis:
      • Plain films usually are normal, but ultrasound may show widening of joint space secondary to swelling.
      • Fluoroscopy may aid in the aspiration of joint fluid for culture.
    • Legg-Calve-Perthes syndrome:
      • AP and frog-lateral radiographs of the pelvis aid in diagnosis and help guide treatment.
      • Plain radiographs may be normal early in the disease, but increased density of the femoral head is an early sign of Legg-Calve-Perthes syndrome.
      • MRI helps show osteonecrosis.
      • Bone scan may help distinguish between Legg-Calve-Perthes syndrome and transient synovitis early in the disease.
      • If bilateral involvement is present, screen hand and knee radiographs to rule out epiphyseal dysplasia or thyroid disease.
    • Transient synovitis:
      • If symptoms have been present for several days, then AP and frog-lateral radiographs are appropriate to rule out a latent osteomyelitis or other chronic processes.
      • Radiographs are normal, but ultrasound may reveal swelling of the capsule and adjacent soft tissue and slight widening of the joint space.
    • SCFE:
      • AP and frog-lateral radiographs of each hip confirm the diagnosis.
      • Early in the disorder, an abnormal widening of the physis is seen.
      • As the slip progresses, the metaphysis appears more lateral relative to the acetabular teardrop.
Miscellaneous
FAQ
Q: Can DDH always be detected by physical examination?
A: No. It is usually, but not always, possible to detect it on routine physical examination. Situations that make detection more difficult include a child who is irritable or who has ligamentous laxity, bilateral abnormalities, or a very mild degree of dysplasia.
 
Q: Should all newborns have screening ultrasound for DDH?
A: Ultrasound leads to some false-positive results and consequent overtreatment. Therefore, it should be used only in the presence of a clinical suspicion of dysplasia, such as an abnormal physical examination, positive family history, or breech birth.

Comments are closed.