Amniotic Band Syndrome (Streeter Dysplasia) Clinical Presentation

Updated: Sep 10, 2020
  • Author: Twee T Do, MD; Chief Editor: Jeffrey D Thomson, MD  more...
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Presentation

History and Physical Examination

Children born with amniotic band syndrome (ABS; also referred to as amniotic band sequence or Streeter dysplasia) are usually full-term or a few weeks premature; in most cases, the pregnancies were uncomplicated. In Light and Ogden's series, the average gestation was 37.5 weeks, with an average birth weight of 3.0 kg. [15]

Although the condition is quite variable in presentation, the most common clinical findings in ABS appear on the extremities (see the image below) and include amputation followed by constriction bands and then acrosyndactyly. Other associated findings include the following:

Image shows the lower limb of a young child born w Image shows the lower limb of a young child born with moderate bands that extend deep to the fascia but do not compromise the neurovascular system.

On the extremities, the distal portion is most often involved, especially the longer central digits of the hand (middle, long, and index fingers). The hands are affected in almost 90% of cases. [19] In rare cases, the thumb or small finger is involved, presumably because of their shorter lengths. The same rule holds true for the feet, where constriction bands most commonly involve the hallux.

Mild band pressure causes only indentations at the base of the phalanx, usually distal to the metacarpophalangeal (MCP) joints. Progressive constriction is the result of the maceration of the indentation and subsequent healing by scar tissue formation. If the compression from the band is severe, lymphatic and vascular compromise may ensue, and the child presents at birth with a swollen engorged digit or limb that may require immediate surgical release. [20]

More commonly, the digit has been amputated in utero. Acrosyndactyly occurs after digital separation is complete, but the fingers become twisted by bands and eventually coalesce. The peripheral digits are brought forward, and residual sinus tracts are usually present in the remnant web space where a probe can be placed—so-called fenestrated syndactyly.

Extremity deformities in ABS are commonly classified into Patterson's four types, as follows:

  • Type I - Simple ring constriction
  • Type II - Ring constriction accompanied by fusion of the distal bony parts, with or without lymphedema
  • Type III - Ring constrictions accompanied by fusion of soft-tissue parts
  • Type IV - Intrauterine amputations

Clubfoot is seen in as many as 25% of cases. This is a mix of paralytic and idiopathic deformities. In 50% of clubfoot cases, a tight band is found around the peroneal nerve, which causes muscle imbalance and clubfoot. [21, 22] In the other 50%, no bands are visible anywhere on the limb. The deformity is thought to arise from lack of space due to oligohydramnios. The clubfoot deformity is typically rigid.

Clinically significant limb-length discrepancy may also be present, and patients need to be sequentially monitored, even after correction of bands and the clubfoot.

Other less common findings include the following:

  • Craniofacial abnormalities, [23, 24, 25] which may occur in as many as 5% of ABS cases
  • Acquired raised limb bands
  • Anterolateral bowing of the tibia with pseudarthrosis