Abstract
Introduction
Many methods are available for distal anchoring of spine-based and rib-based growing rod systems for early-onset scoliosis. One of these methods, pelvic S-hooks, was initially recommended for patients with spina bifida or for those with severe thoracolumbar curves. No study has yet analysed the clinical and radiographic effects of S-hooks on patients with rib-based instrumentation. The purpose of this study is to retrospectively review the results of S-hook pelvic fixation in patients with rib-based instrumentation
Methods
A multicentre, retrospective study, approved by the institutional review board, was undetaken in all patients treated with rib-based constructs using S-hooks for pelvic fixation. Preoperative and postoperative clinical variables, radiological measurements, and the incidence and management of complications were evaluated in patients with a minimum follow-up of 2 years.
Results
44 patients, 26 of whom were girls, were studied and had a mean age at surgery of 71 months. The most common surgical indication was progressive neuromuscular scoliosis. The average preoperative Cobb angle was 64° and at most recent follow-up (mean 45 months) was 53°. The most common construct was dual rods resting over the iliac crest without suture to the iliac crest extending from T3/T4 ribs to the pelvis using domino connectors. 45% of the patients had complications, of which S-hook migration after the initial procedures was the most common. S-hook migration was corrected at the next lengthening with repositioning of the hook to the iliac crest. No correlation was detected between the complication rates and the clinical, radiographic, and surgical technique variables evaluated.
Conclusions
Control of spinal deformities without fusion presents several challenges. S-hooks can migrate off the iliac crest, requiring repositioning of implants during subsequent lengthening. This finding highlights the need to explore different fixation techniques with a stronger attachment to the iliac crest.
