Preliminary outcome of three-dimensional correction for idiopathic scoliosis by vertebral coplanar alignment

English Keywords:Idiopathic scoliosis  Vertebral coplanar alignment  Derotation  Sagittal alignment

English Abstract:

  【Abstract】 Objective：To evaluate the preliminary outcome of vertebral coplanar alignment（VCA） for the management of idiopathic scoliosis（IS）.Method：20 patients with IS undergoing one-stage posterior pedicle screw fixation，VCA correction and allograft fusion were included in this study.There were 15 females and 5 males with the mean age of 15.3 years（range，11 to 21 years）.According to Lenke classification system，there were 14 type 1 and 6 type 2.The mean Cobb angle of the main curve was 67.5°（range，50° to 86°） and the mean thoracic kyphosis was 25.7°（range，5° to 55°）.After correction，the Cobb angle of the main curve and thoracic kyphosis were evaluated.The rib hump（RH），apical vertebral body rib ratio（AVB-R），apical rib spread difference（ARSD） and rotational angle to sacrum（RAsac） were measured to assess the correction of rotational deformity.Result：All patients underwent this surgical protocol successfully without major complications.The average operation time was 164min（range，115 to 196min），and the mean blood loss was 680ml（range，400 to 800ml）.The mean residual Cobb angle of main curve was 20.6°（range，12° to 27°） and the corrective rate was 70.1% with the corrective rate of RH，AVB-R，ARSD and RAsac of 56.3%，29.8%，74.3% and 54.1% respectively.The mean postoperative kyphosis was 21.8°（range，17° to 27°） and the thoracic kyphosis recovered to normal in all patients with no hypokyphosis noted.All patients were followed up for an average of 9 months（range，3 to 12 months）.No decompensation and loss of correction was noted.Conclusion：VCA correction can manage coronal misalignment， recover thoracic alignment and rotational deformity of IS effectively.