Minimally invasive surgery for adolescent idiopathic scoliosis CORRECTION OF DEFORMITY AND PERI-OPERATIVE MORBIDITY IN 70 CONSECUTIVE PATIENTS

Aims The aim of this study was to report a retrospective, consecutive series of patients with adolescent idiopathic scoliosis (AIS) who were treated with posterior minimally invasive surgery (MIS) with a mean follow-up of two years (SD 1.4; 0.9 to 0 3.7). Our objectives were to measure the correction of the deformity and record the peri-operative morbidity. Special attention was paid to the operating time (ORT), estimated blood loss (EBL), length of stay (LOS) and further complications. Patients and Methods We prospectively collected the data of 70 consecutive patients with AIS treated with MIS using three incisions and a muscle-splitting approach by a single surgeon between June 2013 and February 2016 and these were retrospectively reviewed. There were eight male and 62 female patients with a mean age of 15 years (SD 4.5) with a mean body mass index of 19.8 kg/m(2) (SD 5.4). The curves were classified according to Lenke; 40 curves were type 1, 15 were type 2, three were type 3, two were type 4, eight were type 5 and two were type 6. Results The mean primary Cobb angle was corrected from 58.9 degrees (SD 12.6 degrees) pre-operatively to 17.7 degrees (SD 10.2 degrees) post-operatively with a mean correction of 69% (SD 20%, p < 0.001). The mean kyphosis at T5 to T12 increased from 24.2 degrees (SD 12.2 degrees) pre-operatively to 30.1 degrees (SD 9.6 degrees, p < 0.001) post-operatively. Peri-operative (30 days) complications occurred in three patients(4.2%): one subcutaneous haematoma, one deep venous thrombosis and one pulmonary complication. Five additional complications occurred in five patients (7.1%): one superficial wound infection, one suture granuloma and three delayed deep surgical site infections. The mean ORT was 337.1 mins (SD 121.3); the mean EBL was 345.7 ml (SD 175.1) and the mean LOS was 4.6 days (SD 0.8). Conclusion The use of MIS for patients with AIS results in a significant correction of spinal deformity in both the frontal and sagittal planes, with a low EBL and a short LOS. The rate of peri-operative complications compares well with that following a routine open technique. The longer term safety and benefit of MIS in these patients needs to be evaluated with further follow-up of a larger cohort of patients.