Paediatric Hip Conditions (Non-Trauma)

Summary

Condition	Presentation	Radiologic findings	Treatment
Developmental dysplasia of the hip (DDH)	Common in extended breech babies. Positive barlow and ortolani test on screening. Limb length discrepancy in unilateral disease (Galeazzi). Limp may be present as disease progresses and early onset arthritis.	Ultrasound gives the best resolution until 3 – 6 months of age. Shentons line should be continuous on plain film	Splint and harnesses or traction. Osteotomy and hip realignment procedures in later years.
Perthes disease	Hip pain (referred to the knee) between 5 – 12 years of age. Bilateral in 20%	Flattened femoral head on X-ray. Femoral head fragments in untreated cases	Remove pressure from the joint (abduction bracing) and physiotherapy. Usually self-limiting if diagnosed and treated prompltly
Slipped upper femoral epiphysis (SUFE)	Obese male adolescent (10 – 15 years). Hip pain refered to the knee (knee pain is usually present 2 months before hip slipping). Limited internal rotation. Bilateral in 20% of cases	Femoral head displaced and falling inferolaterally. Southwick angle gives indication of disease severity	Bed rest and non-weight bearing. Percutaneous pinning may be perforrmed
Transient synovitis (irritable hip)	Acute hip pain associated with viral infection. Commonest cause of hip pain in children. Presents at 2 – 10 years of age
Juvenile idiopathic arthritis (JIA)	Arthritis occurring < 16 years of age that lasts for more than 3 months. Pauciarticular type involves ≤ 4 joints and accounts for 60% of cases.
Septic arthritis	Acute hip pain associated with systemic upset e.g fever. Severe limitatin of the affected joint.

Developmental Dysplasia of the Hip (DDH)

Developmental dysplasia of the hip (DDH) is an abnormal development of the hip characterized by dysplasia, sublaxation and possible dislocation of the hip. It results from ligamentous laxity and an acetabulum that is too shallow. The femoral head does not sit properly within the acetabulum and can be partially or completely dislocated from the hip joint. DDH ranges from mild to severe and may be present at birth or develop later in life. Diagnosis is confirmed by ultrasound (< 6 months old before the head of femur ossifies) or radiographs and treatment can be conservative using bracing or surgical depending on the age and severity.

DDH is the most common orthopaedic disorder in newborns. It is more common in females (F:M 6:1). The left hip is affected more (60%) and is bilateral in 20% of cases.

Classification of DDH (phases)

Phase	Physical exam
Subluxable	Barlow-suggestive
Dislocatable	Barlow-positive
Dislocated	Ortolani-positive if reducible, Ortolani negative if irreducible

• Risk factors for DDH (Fs)
  • Firstborn child (due to tight spacing in the uterine cavity)
  • Female (due to ligamentous laxity caused by circulating estrogens)
  • Family history of DDH (parents or siblings)
  • Fluid lacking (oligohydramnios)
  • Feet first (breech presentation especially when feet lie near the shoulders e.g. Frank breech)
  • Tight swaddling (especially with the hips and knees straight)
• Associated conditions
  • Congenital muscular torticollis
  • Metatarsus adductus
  • Congenital knee dislocation
• Pathophysiology
  • Maternal and fetal laxity + intrauterine and postnatal malpositioning → dysplasia (deficiency in the anterior and anterolateral acetabulum) → subluxation and dislocation of the femoral head
  • Repetitive sublaxation → thickened articular cartilage (limbus)
  • Chronic dislocation → difficult to reduce and anatomic changes
• Physical examination (< 3 months)
  • Barlow: gently adduct and depress the femur. A palpable click occurs as the hip moves into a dislocated position
  • Ortolani: gently elevate and abduct the femur. A palpable click occurs signifying reduction of a dislocated hip
  • Galeazzi (Allis test): apparent length discrepancy of the femur when the hip is positioned into 90 degrees of flexion i.e. the knee is lower on the affected (dislocated) side when the hips are flexed and the patient is supine
  • Telescoping
  • Asymmetric skin folds
• Physical examination (3 – 12 months)
  • Decreased hip abduction (due to contractures)
  • Leg length discrepancy
  • Klisic test forbilateral dislocation: line from the long finger over the greater trochanter and index finger over the ASIS should point towards the umbilicus. It points halfway between the umbilicus and pubis in dislocation
• Physical examination (> 12 months, walking child
  • Pelvic obliquity
  • Lumbar lordosis (due to hip contractures)
  • Trendelenburg gait (due to abductor insufficiency)
  • Toe-walking (to compensate for shortening of the affected side)
• Investigations
  • Ultrasound of the hip: for patients less than 6 months old
    • Acetabular dysplasia
    • Hip dislocation
  • X-ray of the hip: AP view of pelvis for patients older than 6 months when the ossific nucleus of the proximal femur appears
    • Shenton’s line (should be continuous)
    • Hilgenreiner’s line (femoral head ossification should be inferior to this line)
    • Perkin’s line (femoral head ossification should be medial to this line
    • Delayed ossification of the femoral head
    • Absent acetabular teardrop
  • Arthrogram: to confirm reduction after closed reduction under anaesthesia
  • MRI: to evaluate reduction of hip after closed reduction and spica casting
• Non-operative treatment
  • Abduction bracing with a Pavlik harness: for children < 6 months old with reducible hip. Abduct the hip for a duration of about 12 weeks.
  • Closed reduction and spica cast for children aged 6 – 18 months or those who fail treatment with a Pavlik harness
• Operative treatment
  • Open reduction +/- femoral or pelvic osteotomy for children older than 18 months
• Complications of DDH
  • Avascular necrosis
  • Dislocation
  • Recurrence (10%)
  • Femoral nerve palsy (transient, due to excessive flexion using a Pavlik harness)

Legg-Calve Perthes Disease (LCPD)

Legg-Calve Pertehse disease is an idiopathic osteonecrosis of the femoral head. It commonly occurs in young, active males.

• Signs and symptoms
  • Right hip pain
  • Progressive difficulty walking
• Non-operative treatment
  • Abduction bracing
• Operative treatment
  • Pelvic osteotomies (if needed)

Slipped Capital/Upper Femoral Epiphysis (SCFE/SUFE)

SCFE or SUFE is the displacement of the epiphysis on the femoral head with no history of injury. It may be caused by mechanical overloading which leads to displacement. Slipping typically occurs through the hypertrophic zone of the physis.

More common in obese children (greatest risk). Affects males more than females. Occurs during periods of rapid growth e.g. puberty (age 12 – 13 years). Affects the left hip more than the right.

• Associated conditions (severe endocrine conditions usually present at either <10 years or > 16 years)
  • Hypothyroidism
  • Osteodystrophy of chronic renal failure
  • Excessive growth hormone
• Signs and symptoms
  • Groin, anterior thigh or knee pain
  • Difficulty walking
  • Prefer to sit in a chair with affected leg crossed over the other
  • Symptoms may be present for weeks to several months
• Physical examination
  • Coxalgic, externally rotated gait or Trendelenberg gait
  • Shortening
  • Decreased hip motion
  • Obligate external rotation and abduction with hip flexion (positive Drehmann’s sign)
  • Weakness
• Investigation
  • Pelvic X-ray (AP and frog-leg lateral views):
    • Klein’s line: line drawn along the superior border of the femoral neck will not intersect femoral head (it does so in a normal hip)
    • Epiphysiolysis: growth plate widening or lucency
    • Blurring of femoral metaphysis (metaphyseal blanch sign of Steel)
• Treatment
  • Percutaneous in situ fixation through the femoral neck
  • Contralateral in situ prophylactic pinning (bilateral in situ fixation)
• Complications
  • Osteonecrosis of the femoral head
  • Contralateral SCFE/SUFE
  • Chondrolysis
  • Slip progression
  • Infection
  • Chronic pain
  • Degenerative arthritis
  • Pin associated proximal femur fracture
  • Labral tearing and degeneration