Pedicle Screw Versus Hybrid Construct Instrumentation In Adolescent Idiopathic Scoliosis:Meta-analysis Of Thoracic Kyphosis

Study design A quantitative meta-analysis was conducted on publishing studies reporting results of spinal surgery in AIS with instrumentation of pedicle screw or hybrid construct. Objective The primary objective is to get overview of the power to restore thoracic kyphosis using two different instrumentations.Summary of background data Over the past years, surgery has mainly focused on correcting the coronal curve, but nowadays the aims of posterior fusion and instrumentation are to achieve a stable, well-balanced spine in the coronal as well as in the sagittal planes. Method A Pubmed and Embase search was conducted using combinations of the keywords "hybrid construct" or" pedicle screw" with "adolescent idiopathic scoliosis" up to Oct2013. A hand search of reference lists of obtained articles was also performed.Result24studies were identified and included in this meta-analysis. Of this,12included pedicle screw group only,5included hybrid construct group only, and7included both groups. The total number of patients was1,615.Age ranged from9to26with a mean15. For pedicle screw group, we got SMD(95%CI) as0.40(0.31,0.50). I-squared=91.4%.For hybrid construct group, we got SMD(95%CI) as0.15(0.04,0.26).Both intervals of SMD lied in positive value side. Overall SMD(95%CI) was0.30(0.23,0.37). The positive value of SMD means thoracic kyphosis improves after surgery, while negative value means kyphosis loss after surgery.Conclusion Due to the heterogeneity of result, we may just say that it has tendency for both instrumentation to restore thoracic kyphosis. Hybrid construct seems to be more powerful in restoring kyphosis than pedicle screw. No factor was found to be considered as important factor influencing the kyphosis result.