Adolescent idiopathic scoliosis: a prospective randomised trial protocol comparing clinical and radiological outcomes in minimally invasive surgery versus standard posterior spinal fusion in a single-centre, the Rizzoli Orthopaedic Institute, Bologna, Italy.

INTRODUCTION

Minimally invasive spine surgery (MISS) has been shown to be safe and effective in adolescent idiopathic scoliosis (AIS) correction, even though there is no consensus on which treatment provides the best results.

METHODS AND ANALYSIS

The present study will be a randomised controlled trial with allocation 1:1. We will enrol 126 patients with Cobb≤70° undergoing AIS surgery. Patients will be divided into two groups, according to a randomisation list unknown to the surgeons. Group 1 will be treated with posterior spine fusion and group 2 with MISS. MISS technique: two midline noncontiguous skin incisions of 3 cm in length, 3-4 segments (6-8 pedicles screws) instrumented per skin incision, uniplanar and polyaxial pedicle screws inserted bilaterally on each side of the proximal and distal levels, rod translation manoeuvre and C-D manoeuvre performed on the distal part. Clinical and radiological follow-ups will be performed for 5 years. Values of Cobb angles degrees will be collected to study the correction rate of the structural major curve. Postoperative and preoperative anterior-posterior (AP) direct radiography will be compared with the last follow-up examination. Operative time, preoperative haemoglobin (Hb) and second postoperative day Hb, full length of hospitalisation, time to achieve verticalisation and time to remove the drainage will be recorded. Numeric Rating Scale (NRS) medium score will be assessed immediately after surgery and during the whole postoperative rehabilitation treatment to estimate pain reduction. Complications will be collected postoperatively and throughout the whole follow-up period.Moreover, questionnaires will be administered at follow-up (NRS, Scoliosis Research Society-22 and Oswestry Disability Index) for the clinical assessment.

ETHICS AND DISSEMINATION

The study protocol has been approved by the local ethic committee Area Vasta Emilia Romagna Centro. Written informed consent will be collected for all the participants. Findings of this study will be disseminated through peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

NCT05860673.