Review Question - QID 4995

A left thoracic curve is an abnormal finding and warrants further work-up with a total axis MRI in order to rule out concomitant neurologic abnormalities such as a spinal cord cyst and/or syrinx.

In adolescent idiopathic scoliosis (AIS), the most commonly occurring curve is a right thoracic curve. Left thoracic curves are not as common, and warrants total axis MRI in order to rule out concomitant central axis abnormalities. This is imperative not only during initial work-up, but most importantly for operative planning.

Spiegel et al. performed a a retrospective radiographic review on 41 patients with scoliosis associated with a Chiari I malformation and/or syringomyelia. Approximately 50% of patients had an "atypical" pattern (left thoracic, double thoracic, triple, long right thoracic). The authors recommend that MRI should be considered in these patients.

Gillingham et al. provides a thorough review of early onset scoliosis and notes the relatively high incidence of concurrent central axis abnormalities, even in patients with normal neurologic exams. Rates have been reported upwards of 21.7%, with malformations including Chiari Type 1, dural ectasias, syrinx, and spinal cord cysts.

Figure A exhibits a left thoracic curve. Further imaging in this patient revealed a syrinx which required decompression.

Incorrect answers:
Answer 1: custom orthosis and non-operative treatment is not the best option, nor the next best step.
Answer 2: Physical therapy will have no bearing on the treatment of this patients thoracic curve.
Answer 3: Bending radiographs may be helpful further down the treatment line, however, at this current time is not the next best step.
Answer 4: Total spine CT may help if any bony abnormalities or failure to formations are noted, however, those are more typical in congenital or very early onset cases and is not the next best step here.