Selective anterior thoracolumbar/lumbar fusion and instrumentation in adolescent idiopathic scoliosis patients.

Background: Selective anterior thoracolumbar/lumbar (TL/L) fusion and instrumentation in adolescent idiopathic scoliosis (AIS) patients with a structural major TL/L curve and a nonstructural minor thoracic curve is rarely reported. We investigate the correction results of these patients.
Methods: By reviewing the medical records and roentgenograms of AIS patients undergone selective anterior TL/L fusion and instrumentation, Cobb angle, correction rate of the major and minor curves, coronal balance, lowest instrumented vertebra (LIV) tilt, coronal disc angle immediately below the LIV (LIVDA) and radiographic shoulder height (RSH) were measured and analyzed.
Results: Forty patients were included. For the major TL/L curve, the mean coronal Cobb angle before and after operation were 43.9° and 8.7°, respectively, with an average correction rate of 80.2% (P = 0.000). While for the minor thoracic curve, the mean coronal Cobb angle before and after operation were 27.2° and 14.3°, respectively, with an average spontaneous correction rate of 47.4% (P = 0.000). At final follow-up, the coronal Cobb angles of the major and minor curves were 13.7° and 17.1°, respectively, with a mean correction loss of 5.0° and 2.9°, respectively. The coronal balance before and after operations was 13.2 mm and 11.5 mm, respectively. At the final follow-up, it turned to 5.6 mm, which was much better than that after operation (P = 0.001). The mean LIV tilt was 23.5° before operation, and was significantly improved after operation (8.3°, P = 0.000). At final follow-up, it was well maintained (10.6°). The LIVDA averaged 3.5° before operation, and aggravated to 5.5° after operation (P = 0.100) and 7.4° at final follow-up (P = 0.012), respectively. The RSH was 7.3 mm before operation, 5.6 mm after operation, and 2.2 mm at the final follow-up. The RSH at the final follow-up was significantly improved compared with that after operation (P = 0.002).
Conclusions: Selective anterior TL/L fusion and instrumentation can get good correction results of both curves, with good results of the coronal balance and RSH in AIS patients, while a larger LIVDA.