Minimally Invasive Surgery for Neuromuscular Scoliosis

Results and Complications at a Minimal Follow-up of 5 Years

Mathilde Gaume, MD; Claudio Vergari, MD; Nejib Khouri, MD; Wafa Skalli, MD, PhD; Christophe Glorion, MD, PhD; Lotfi Miladi, MD


Spine. 2021;46(24):1696-1704. 

In This Article

Patients and Methods

Study Design and Data Collection

Medical charts of the first 100 consecutive patients who underwent surgery for neuromuscular scoliosis at our department between 2011 and 2015 were reviewed. The study was approved by the appropriate ethics committee (CPP, ID-EUDRACT #2014-A01043–44). Informed consent was obtained from parents/guardians of all participants. The original minimally invasive bipolar technique used in these patients has been previously described.

Patients were operated under intraoperative traction and evoked potential monitoring. Two short incisions, one thoracic and one lumbar, were made to insert the anchors. The instrumentation extends from T1 to the sacrum, proximally with a double pediculosupralaminar claw and distally why iliosacral screws. Two long precurved rods (diameter 5.5 mm) are inserted in an intramuscular way from the proximal wound to the distal one and attached proximally to the hooks and distally to two short rods fixed inside the iliosacral connectors. Side-to-side connectors and cross-links connect the rods to build a solid sliding frame construct.

In this technique, the correction is obtained through distraction maneuvers that are applied at the distal part of the sliding construct, without further rod manipulations. The bipolar concept relies on a continuous tension between the proximal and the distal points of fixation obtained with rod lengthening on demand. Rods were lengthened using the previous distal incision to access the side-to-side connectors. Lengthening procedure was performed according to the following indications:

  • to perfect pelvic correction in case of major residual pelvic obliquity, in particular thanks to the possibility of performing asymmetrical lengthening of the rods;

  • to improve a persistent trunk imbalance in the frontal or sagittal plane.

The amount of rod lengthening was froml5 to 30 mm.

For each patient, the following radiographic parameters were recorded before surgery, immediately after surgery, and at last follow-up: stages of skeletal maturity as reflected by the Risser sign, Cobb angle, pelvic obliquity, and thoracic kyphosis. Screw loosening was defined as a radiolucent area (≥1 mm in circumference) around the screw, noted on plain radiograph by at least two observers. Radiographic measurements were performed using previously described methods.[14,15] All types of complications were reviewed including implant failure (e.g., malposition of the ilio-sacral screw, hooks migration, and implant breakage) and infections. Mean body weight was recorded preoperatively and at latest follow-up.

Statistical Analysis

Variables were described as mean (range). Changes in radiological parameter values from baseline to last follow-up were evaluated by applying the pairwise Student t test. P values <0.05 were considered significant. Complications were described as n (%).