Pedicle screw versus hybrid instrumentation in adolescent idiopathic scoliosis A systematic review and meta-analysis with emphasis on complications and reoperations

Background: Incidence of complications and reoperations between pedicle screw (PS) and hybrid instrumentations (HI) are still controversial in adolescent idiopathic scoliosis (AIS) patients. A systematic review and meta-analysis were performed to compare overall complications, reoperations, and radiographic outcomes between the 2 constructs. Methods: Strictly followed the PRISMA 2009 guidelines, the MEDLINE, EMBASE, and the Cochrane Library databases were used to search for literatures up to April 2016, addressing PS versus HI in AIS patients. The Newcastle-Ottawa scale was adopted to assess the quality of the studies. Data on complications, reoperations, Cobb angle of major curve, thoracic kyphosis, and proximal junctional measurement were extracted from the included studies. RevMan 5.3 and SPSS 21.0 were used for statistical analysis. Results: Twenty-four case-control studies with a total of 3042 AIS patients (1582 PS, 1460 HI) were included, consisting of 1 randomized controlled trial, 1 prospective study, and 22 retrospective studies. Decreased overall complications (95% CI 0.42-0.87, P=.007; I-2=38%) and reoperations (95% CI 0.22-0.62, P=.0001; I-2=0%) were found in PS group compared with HI group. As regard to reasons for reoperations, increased incidence of pseudarthrosis (P=.005), dislodged instrumentation (P=.005), and deep infection (P=.016) occurred in HI group. PS group achieved a better coronal correction (95% CI-7.06 to -4.54, P<.00001; I-2=34%), but HI group was more powerful in restoring thoracic kyphosis (95% CI-7.88 to -3.70, P<.00001; I-2=60%), and no significant differences were found in proximal junctional measurement (95% CI -0.88 to 1.54, P=.59; I-2=0%) between the 2 constructs. Conclusion: Compared with hybrid instrumentation, pedicle screw construct provides better coronal correction but less thoracic kyphosis restoring, with decreased incidence of overall complications and reoperations in AIS patients. As regard to the pedicle screw construct, the most common reasons for reoperation are malposition, deep infection, pseudarthrosis, and prominent implant.