Min Implants Max Outcomes Clinical Trial
Condition: Scoliosis; Adolescent Idiopathic Scoliosis
MeSH terms: Scoliosis
Study type: Interventional

Summary: 
      Objectives Primary objective: Determine if there is a clinically significant difference in
      percent Cobb curve correction in a low- vs. high-implant density cohort through a prospective
      randomized controlled trial.

      Design and Outcomes Randomized clinical trial of equivalence to test the efficacy and safety
      of low vs. high implant density instrumentation for spine deformity surgery in AIS patients
      with Lenke IA curve patterns.

      Interventions and Duration Intervention: low-implant density group or high-implant density
      group. Duration: 2 years. Sample Size and Population Target population: 10 to 17 years old
      with AIS who will undergo instrumented spinal fusion. Sample size needed (power = 90%) is 174
      subjects with 87 in each group.
    

Detailed description: 
      The MIMO Study Group proposes to conduct a prospective randomized controlled trial in order
      to determine whether a low implant density cohort has equivalent clinical and radiographic
      results to a high implant density cohort. This study is proposed as a trial of equivalence.
      The null hypothesis is that significant differences exist in percent major Cobb angle
      correction between high- and low-implant density cohorts for Lenke 1A curve types, the most
      common scoliotic curve pattern (73). Consecutive qualifying patients will be screened and
      enrolled by high-volume spine surgeons at 14 sites and randomized to spinal instrumentation
      with a low- or high-density screw pattern. Patients will return at 3-months, 1-year, and
      2-years for exam, radiographs, and collection of patient-reported outcome scores. The Harms
      Study Group Foundation will serve as a collaborating organization and will provide database
      development and management, secure online data collection, centralized radiographic
      measurements, and data quality control. The University of Minnesota team will lead study
      design, protocol development, IRB/data use agreement contracts, patient randomization, and
      statistical analysis, including quarterly data review. Imaging will be obtained either with
      an EOS system or using a calibration belt during the radiographs, which allows for subsequent
      with the 3D modeling of the deformity. Six enrolling sites currently have this capability
      (EOS - Montreal, St. Louis, Iowa, Mayo, DuPont, and San Diego). An additional five sites
      already have calibration belts - Dallas, New York, Baltimore, Boston, U. of Rochester), and
      new calibration belts will be fabricated for the additional sites. The Montreal site will
      supervise collection of radiographic data with 3D capability and assist with troubleshooting
      and radiographic quality control. Although the study is primarily powered to detect change in
      percent correction of the major coronal curve, preliminary data will be gathered on axial and
      sagittal plane correction as well as complications, surgical factors, and patient-reported
      outcomes.
    

Intervention name(s): Maximum Number of Screws; Minimum Number of Screws
Intervention type(s): Procedure; Procedure
Intervention description(s): The tools used for this arm of study are FDA approved with section 510 (k) K122433. These screws are regularly used in all procedures pertaining to Cobb angle correction surgeries outside of the context of this study.; The tools used for this arm of study are FDA approved with section 510 (k) K122433. These screws are regularly used in all procedures pertaining to Cobb angle correction surgeries outside of the context of this study.
Other intervention name(s): Pedicle Screw Spinal System; Pedicle Screw Spinal System
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: Scoliosis; Cobb Angle; Screw Density; Outcomes Measures