SUMMARY

• emihypertrophy is an idiopathic condition that can also be caused by a variety of syndromes, and presents with asymmetry between the right and left sides of the body to a greater degree than can be attributed to normal variation.

• Diagnosis is made clinically with abnormal asymmetry defined as a 5% or greater difference in length and/or circumference.

• Treatment is observation with or without shoe lifts for leg length differences < 2 cm at skeletal maturity. Surgical intervention is indicated for leg length differences > 2 cm, with different techniques depending on the discrepancy magnitude and remaining skeletal growth.

EPIDEMIOLOGY

• Pathophysiology

  • most common causes are

    • idiopathic (non-syndromic)

    • syndromic

      • neurofibromatosis 

      • Beckwith-Wiedemann syndrome 

      • Klippel-Trenauney syndrome

      • Proteus syndrome

• Associated conditions

  • orthopaedic manifestations

    • scoliosis (compensatory)

    • peripheral nerve entrapment (rare)

  • medical conditions & comorbidities

    • malignant intra-abdominal tumors

      • Wilm's tumor (most common)

        • perform serial abdominal ultrasounds (every 3 months) until age 7 to rule out Wilm's tumor

        • then physical exam every 6 months until skeletal maturity

      • adrenal carcinoma

      • hepatoblastoma

    • genitourinary abnormalities

      • medullary sponge kidneys

      • polycystic kidney

      • inguinal hernias

CLASSIFICATION

• • Congenital classification

    • congenital

      • total

        • involvement of all organ systems

      • limited

        • only muscular, vascular, skeletal, or neurologic involvement

          • classic (ipsilateral upper and lower limbs)

          • segmental (a single limb)

          • facial 

          • crossed

    • acquired

      • very rare

      • can result from injury, infection, radiation or inflammation

  • Syndromic classification

    • non-syndromic (isolated)

    • syndromic (part of a clinical syndrome)

• PRESENTATION

  • Physical exam

    • findings rarely apparent at birth, manifest during growth

    • skin often thicker on involved side

    • more hair on corresponding side of the head

    • limb circumference asymmetric

    • leg-length discrepancy (LLD)

• IMAGING

  • Radiographs

    • AP + lateral of affected limb may demonstrate enlargement of bone and soft tissue 

      • osseous maturation may be seen

  • Abdominal ultrasound

    • indications

      • perform serial abdominal ultrasounds (every 3 months) until age 7 to rule out Wilm's tumor

STUDIES

• Renal function tests

• Serum alpha-fetoprotein

  • screen for embryonal tumors

TREATMENT

• Nonoperative

  • observation, shoelift, corrective shoes

    • indications

      • < 2 cm projected LLD at maturity

• Operative

  • surgical correction

    • indications

      • based on principles of leg length discrepancies