The determination of upper instrumented vertebra in anterior selective fusion on the correction outcomes of Lenke type 5 idiopathic scoliosis / 中华骨科杂志

ABSTRACT

Objective To investigate the influence of fusion to upper end vertebra(UEV)or not on the correction outcomes of Lenke type 5 idiopathic scoliosis with anterior selective fusion.Methods From January 2002 to December 2006,36 AIS patients with a Lenke type 5 curve received anterior single-rod selective fusion and had a minimum 2-year follow-up.According to the level of upper instrumented vertebra,the patients were divided into two groupsGroup A(n=21),fused to UEV,and Group B(n=15),fused to the vertebra below UEV.Patients of Group A and B had a mean age of 15.3 and 15.5 years,a mean thoracolumbar/lumbar curve of 46.2° and 46.7°,and a mean proximal thoracic curve of 26.3° and 29.6°,respectively.During the surgery,average 5.3 and 4.8 levels of vertebrae were fused in Group A and B,respectively.Results Group A and B had a mean follow-up of 31 and 33 months,respectively.The correction rate of major curves in Group A was marginally higher than in Group B(79％ versus 70％,P=0.062),and the spontaneous correction rate of proximal curves in Group A was higher than in Group B(46％ versus 29％,P=0.044).Regarding the pre-operative sagittal profile,similar lumbar lordosis and sacral slope were observed between both groups,and a slight negative balance was maintained.Thoracic kyphosis showed a mild increment in both groups.Thoracolumbar junctional kyphosis resulted in a trivial kyphotic trend.Proximal junctional measurement showed a slight increment in kyphosis,and instrumented segment angle displayed a decreasing lordotic trend.Conclusion Fusion to UEV in anterior selective fusion of Lenke type 5 curve might lead to a better correction of the thoracolumbar/lumbar curve and the unfused proximal thoracic curve,while have no significant influence on the sagittal reconstruction.