Adolescent idiopathic thoracic scoliosis: apical correction with specialized pedicle hooks

Forty-one patients with thoracic adolescent idiopathic scoliosis (AIS) trea ted with only a posterior spine fusion using specialized pedicle hooks (SPH ) (hooks augmented with 3.2-mm screws) at the apex of the curve were review ed in order to assess the effectiveness of this correction method. Inclusio n in the study group required a minimum of 2 years' follow-up and the same strategy of correction where the apical vertebrae (3 or 4 vertebrae on the concave side) were instrumented with SPH. The mean preoperative Cobb angle was corrected from 55 degrees (42 degrees-80 degrees) to 18 degrees (67%) p ostoperatively and to 23 degrees (58%) at the last follow-up (28-50 months) for a flexibility index of 46%. Apical vertebral translation was corrected to 70% at the last follow-up. Thoracic kyphosis remained unchanged, from 2 3 degrees to 26 degrees, and the lumbar lordosis went from -53 degrees to - 59 degrees, The lumbar curve was corrected from 38 degrees to 18 degrees Co ronal balance improved from 10 to 1 mm; shoulder balance was improved from 15 to 5 mm. The rib hump was improved from an average of 30 mm preoperative ly to 15 mm postoperatively, but only to 25 mm at the last follow-up (17% o f correction). One case of a spastic bladder was observed postoperatively, which resolved completely after 8 months. Three patients had to have their instrumentation removed because of pain, There was no complication related to the use of the SPH. The authors conclude that apical correction with SPH allows effective scoliosis correction without spinal distraction and does not require supra- or infralaminar hook in the spinal canal.