Basic principles of correction of severe scoliotic deformities using pedicle screw fixation

Ilya Shavyrin


Objective: To determine the effectiveness of surgical treatment of patients with idiopathic scoliosis who have severe spinal deformity, using all pedicle screw and hybrid constructs.

Material and Methods: Retrospective analysis of the results of treatment of 34 patients aged 15 to 27 years old with severe scoliosis, operated on using pedicle screws. A comparison group consisted of 22 patients, who were operated on using hybrid constructs. Patients from both groups were compared according to the following parameters: pre/postoperative Cobb angle, mobility according to traction test, global sagittal/frontal balance, apical vertebral rotation, operative time, intraoperative blood loss, number of instrumented vertebrae, loss of correction within 24 months.

Results: In group A (pedicle screw fixation) compared to group B (hybrid spinal fixation) patients had better results in the following parameters: postoperative correction was 48% and 41%, apical vertebral rotation decreased from 78° to 55° (30%) and from 74° to 59° (21%), correction of global frontal/sagittal balance from 39/25 mm to 14/12 mm (64%/52%) and 35/26 mm to 16/15 mm (55%/43%) between treatment groups, respectively. These results suggest a better trunk balance and greater postoperative correction in patients with all pedicle screw fixation. Smaller values of loss of correction of the major curve, and a slight increase of thoracic kyphosis in the postoperative period (24 months) 3.8%/4.3% in group A vs. 6.2%/7.5% in group B, indicate a higher reliability and stability of metal with an «all screw» fixation.