Review Question - QID 219548

Patients who received a fusion extending caudad to the touched vertebra (TV) tend to do better, whereas those with fusions cephalad to the TV sustain more truncal shift and a higher likelihood of poor outcomes long term.

Adolescent idiopathic scoliosis is a coronal plane spinal deformity which most commonly presents in adolescent girls from ages 10 to 18. Diagnosis is made with full-length standing PA and lateral spine radiographs.  Treatment can be observation, bracing, or surgical management depending on the skeletal maturity of the patient, magnitude of deformity, and curve progression. The last touched vertebra is defined as the last cephalad vertebra touched by the central sacral vertical line.

Lenke et al. developed a new classification system with three components: curve type, a lumbar spine modifier, and a sagittal thoracic modifier. They reported that this new two-dimensional classification of adolescent idiopathic scoliosis, as tested by two groups of surgeons, was shown to be much more reliable than the King system. They concluded that additional studies are necessary to determine the versatility, reliability, and accuracy of the classification for defining the vertebrae to be included in an arthrodesis.

Beauchamp et al. reviewed the lowest instrumented vertebra (LIV) in patients with adolescent idiopathic scoliosis. They developed a simple and reproducible method for selection of the LIV in patients with Lenke type-1 (main thoracic) and 2 (double thoracic) curves and investigated its effectiveness in producing optimal positioning of the LIV at 5 years of follow-up. They noted that in 86.6% of patients, the LIV was selected at or immediately adjacent to the TV. They concluded that selecting the TV as the LIV in patients with Lenke type-1 and 2 curves provides acceptable positioning of the LIV at long-term follow-up.

Incorrect Answers:
Answer 2: Fusions extending caudad to the touched vertebra is recommended
Answers 3-5: Patients that received a fusion extending caudad to the TV did well, but those who were fused cephalad to the TV sustained more truncal shift and a higher likelihood of poor outcomes long term.