The effect of surgical approaches on postoperative sagittal profile reconstruction following selective thoracolumbar fusion for Lenke type 5 adolescent idiopathic scoliosis / 中华骨科杂志

ABSTRACT

Objective To compare the effects of anterior or posterior selective thoracolumbar/lumbar fusion (ASF or PSF) on the reconstruction of sagittal profile in Lenke type 5 adolescent idiopathic scoliosis (AIS).Methods A total of 102 Lenke type 5 AIS patients who underwent ASF or PSF from January 2005 to December 2010 with a minimum of 2 years follow-up were retrospectively evaluated.Fifty-six patients underwent ASF,while 46 patients underwent PSF.Pre-and postoperative radiological parameters were measured as followscurve magnitude of thoracolumbar/lumbar (TL/L) and thoracic curve,thoracic kyphosis (TK),lumbar lordosis (LL),sacral slope (SS),sagittal vertical axis (SVA),thoracolumbar junctional kyphosis (TJK),instrumented segments angle (ISA),and proximal junctional angle (PJA).Results The mean follow-up duration was 6.1±2.1 years and 5.3±1.5 years in ASF and PSF group respectively.Preoperative radiographic parameters and demographic data showed no significant difference between two groups.The fusion levels in ASF group were shorter than that in PSF group (5.3±0.5 vs.5.9±0.8,P＜0.05),where as the distal preserved motion segments were similar between two groups (1.8±0.7 vs.1.7±0.7,P＞0.05).The correction rate of the TL/L curve was 73.2％±6.9％ in ASF group and 74.8％±10.8％ in PSF group at 3 month after surgery,with a 3.8％±8.7％ and 2.0％±0.2％ of correction loss at final follow-up.Thoracic curve was corrected spontaneously in both groups,and the correction rate of TL/L and thoracic curve was similar between two groups at final follow-up.In both groups,TK increased after surgery and increased at final follow-up compared to that after surgery (P＜0.05).LL decreased in ASF group after surgery (P＜0.05) and remained unchanged at final follow-up.In PSF group,LL remained unchanged after surgery and increased at final follow-up compared to that after surgery (P＜0.05).SS decreased after surgery in ASF group and increased at final follow-up compared to that after surgery (P＜0.05).In PSF group,SS increased after surgery and increased at final follow-up compared to that after surgery (P＜ 0.05).SVA and TJK decreased in both groups after surgery and increased at final follow up compared to that after surgery (P＜ 0.05).ISA remained unchanged after surgery and decreased at final follow-up compared to that after surgery in ASF group (P＜ 0.05).In PSF group,ISA increased after surgery (P＜0.05) and remained unchanged at final follow-up.PJA increased after surgery in both groups,and increased at final follow-up compared to that after surgery in PSF group (P＜0.05).At 3 month after surgery,LL was larger in PSF group.At final follow-up,LL,ISA and PJA was significantly larger in PSF group (P＜0.05).In ASF group,three patients had pseudarthrosis,one had rod breakage,three had adding-on phenomenon,and one had proximal junctional kyphosis (PJK).In PSF group,five patients had PJK and one had adding-on phenomenon.SRS-22 scores showed no significant difference between two groups.Conclusion When Lenke type 5 AIS patients were treated with selective TL/L fusion,coronal correction could be obtained by both ASF and PSF.In sagittal plane,PSF can offer larger restoration of LL and better maintenance of lordosis in the instrumented segment than those in ASF.Additionally,the incidence of PJK in PSF group was higher than that in ASF group.