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/m2 (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° (sd 12.6°) pre-operatively to 17.7° (sd 10.2°) post-operatively with a mean correction of 69% (sd 20%, p < 0.001). The mean kyphosis at T5 to T12 increased from 24.2° (sd 12.2°) pre-operatively to 30.1° (sd 9.6°, 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. Cite this article: Bone Joint J 2017;99-B:1651-7.
Keywords: Adolescent idiopathic scoliosis; Correction of deformity; Minimally invasive surgery; Peri-operative morbidity.
©2017 The British Editorial Society of Bone & Joint Surgery.