title: Minimally invasive scoliosis surgery assisted by O-arm navigation for Lenke Type 5C adolescent idiopathic scoliosis: a comparison with standard open approach spinal instrumentation.
abstract: OBJECTIVE Recently, minimally invasive scoliosis surgery (MISS) was introduced for the correction of adult scoliosis. Multiple benefits including a good deformity correction rate and fewer complications have been demonstrated. However, few studies have reported on the use of MISS for the management of adolescent idiopathic scoliosis (AIS). The purpose of this study was to investigate the outcome of posterior MISS assisted by O-arm navigation for the correction of Lenke Type 5C AIS. METHODS The authors searched a database for all patients with AIS who had been treated with either MISS or PSF between November 2012 and January 2014. Levels of fusion, density of implants, operation time, and estimated blood loss (EBL) were recorded. Coronal and sagittal parameters were evaluated before surgery, immediately after surgery, and at the last follow-up. The accuracy of pedicle screw placement was assessed according to postoperative axial CT images in both groups. The 22-item Scoliosis Research Society questionnaire (SRS-22) results and complications were collected during follow-up. RESULTS The authors retrospectively reviewed the records of 45 patients with Lenke Type 5C AIS, 15 who underwent posterior MISS under O-arm navigation and 30 who underwent posterior spinal fusion (PSF). The 2 treatment groups were matched in terms of baseline characteristics. Comparison of radiographic parameters revealed no obvious difference between the 2 groups immediately after surgery or at the final follow-up; however, the MISS patients had significantly less EBL (p < 0.001) and longer operation times (p = 0.002). The evaluation of pain and self-image using the SRS-22 showed significantly higher scores in the MISS group (p = 0.013 and 0.046, respectively) than in the PSF group. Postoperative CT showed high accuracy in pedicle placement in both groups. No deep wound infection, pseudarthrosis, additional surgery, implant failure, or neurological complications were recorded in either group. CONCLUSIONS Minimally invasive scoliosis surgery is an effective and safe alternative to open surgery for patients with Lenke Type 5C AIS. Compared with results of the open approach, the outcomes of MISS are promising, with reduced morbidity. Before the routine use of MISS, however, long-term data are needed.
mesh_terms: D000293:Adolescent; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D019060:Minimally Invasive Surgical Procedures / Q000379:methods*; D065289:Pedicle Screws; D012189:Retrospective Studies; D012600:Scoliosis / Q000000981:diagnostic imaging* / Q000601:surgery*; D013123:Spinal Fusion / Q000379:methods; D015898:Tomography Scanners, X-Ray Computed; D016896:Treatment Outcome
keywords: AIS = adolescent idiopathic scoliosis; AVR = apical vertebral rotation; AVT = apical vertebral translation; CB = coronal balance; EBL = estimated blood loss; LL = lumbar lordosis; Lenke Type 5C; MISS = minimally invasive scoliosis surgery; O-arm navigation; PSF = posterior spinal fusion; SRS-22 = 22-item Scoliosis Research Society questionnaire; SVA = sagittal vertical axis; T = Cobb angle of thoracic curve; TK = thoracic kyphosis; TL/L = Cobb angle of thoracolumbar/lumbar curve; adolescent idiopathic scoliosis; minimally invasive scoliosis surgery; spine