Early Rebalancing Following Selective Lumbar Fusions in Adolescent Idiopathic Scoliosis

Results: (See Table) Coronal decompensation increased 28% (p=0.03) at the 1 week period; however, spontaneous correction occurred between 1 week and 3 month follow-up such that correction at 3 months (56%, p=0.006) and 1 year (64%, p<0 .001) were not statistically different (p="0.45)." No significant improvement in T1 tilt or proximal thoracic curve Cobb magnitude at any time period found. Shoulder balance, measured by clavicular tilt, worsened 36% 1 week but improved continually until achieving 46% correction year. Main spontaneous averaged 31% (p<0.001) and remained similar (39%, p<0.001) through latest follow-up Apical translation increased then diminished subsequent intervals. Lumbar (75%) was to year postop (73%)(p="0.84)." Mean kyphosis lordosis all periods, although sagittal balance varied widely from (range -6.5 +9.5cm, std dev. 3.8) -7 +2cm, 2.0).

Discussion: Early decompensation following selective lumbar fusion typically corrects within 3 months postoperatively. The thoracic curve exemplifies early Cobb correction followed by subsequent improvements in apical translation. Shoulder balance, also initially worsened after surgery, continues to improve through 1 year follow-up. The lumbar curve and EIV tilt remain unchanged from immediate post-op through 1 year follow-up.