Comparative effectiveness of implant density

Comparative effectiveness research provides information on the benefits and complications of specific treatments and can guide spine surgeons to best-quality practices. Although orthopedic implants comprise more than 25% of the perioperative costs for adolescent idiopathic scoliosis (AIS), there are few high-level studies comparing the various implant types, patterns, and number. Numerous studies have shown the superiority of all pedicle–screw constructs over hook-and-hybrid constructs. A wide variety of pedicle screw numbers, densities, and configurations are used in clinical practice. Many small studies indicate no significant difference in clinical outcomes between low-implant density and high-implant density constructs for the surgical treatment of moderate AIS, but these are likely underpowered. More work is needed to determine the appropriate number and distribution of implants for specific curve patterns to optimize the surgical care of AIS patients.