Clinical Outcomes of Nitinol Staples for Preventing Curve Progression in Idiopathic Scoliosis

Background Data: Although bracing for idiopathic scoliosis is moderately successful, its efficacy has been called into question and it carries associated psychosocial ramifications. In this study we report the background, rationale, indications, surgical techniques, and early results of vertebral body stapling (VBS) in patients with idiopathic scoliosis. Methods: We reviewed the literature on growth modulation of the growing spine and the concepts behind the use of VBS as a fusionless strategy. The indications are derived from retrospectively reviewed patients with idiopathic scoliosis treated with VBS followed for a minimum of 2 years. Indications for staple use included: (a) age < 13 years in girls and 15 in boys, (b) Risser 0 or 1 and/or 1 year of growth remaining on wrist radiograph, (c) coronal curve < 45 degrees with minimal rotation and flexible to < 25 degrees on a side bending radiograph, and (d) sagittal thoracic curve < 40 degrees. Results: Thoracic curves measuring < 35 degrees had a success rate of 77.7%. Curves which reached <= 20 degrees on first erect radiograph had a success rate of 85.7%. Thoracic curves greater than 35 degrees were not successful and require alternative treatments. Lumbar curves demonstrated a success rate of 86.7%. Conclusions: Some patients with idiopathic scoliosis with moderate curves (25 to 45 degrees) and high risk of progression can be safely treated with VBS as an alternative to bracing.