Floman et al., Vertebral growth modulation by posterior dynamic deformity correction device in skeletally immature patients with moderate adolescent idiopathic scoliosis.3

Retrospective study to determine if ApiFix modulated growth in skeletally immature AIS patients. Outcomes include:

  • Curve reduction at final follow-up was significant for all three Risser groups:
    • Risser Grade 0-1: average preoperative curve of 47.6 degrees to 26.4 degrees at final follow-up (p < 0.05)
    • Risser Grade 2-3: average preoperative curve of 46.0 degrees to 20.4 degrees at final follow-up (p < 0.05)
    • Risser Grade 4-5: average preoperative curve of 41.5 degrees to 26.2 degrees at final follow-up (p < 0.05)
  • Delta wedging at the apical vertebrae varied among the three Risser groups with Risser 0-1 patients showing significant reduction from pre-op wedging of 9.5 degrees to 5.4 degrees at final follow-up (p < 0.05)
  • Four patients underwent revision surgery, 0 patients converted to fusion

Floman et al., Surgical management of moderate adolescent idiopathic scoliosis with a fusionless posterior dynamic deformity correction device: interim results with bridging 5–6 disc levels at 2 or more years of follow-up.4

Retrospective review of ApiFix patient outcomes, which include:

  • 46% major curve correction: mean pre-operative curve of 47 degrees reduced to 25 degrees at final follow up (p < 0.05)
  • 82% of patients had final Cobb angle measured ≤ 30 degrees
  • 18% of patients underwent revision surgery
  • Under static compression to failure testing, the system failed under loads higher than 3000N, which is 400% of human body weight.
  • Dynamically, the system held 700N for 10 million cycles (MC).
  • Wear rate was measured for the polyaxial joints and ratchet mechanism. Total steady-state wear rate was 0.074 mg/MC, which is superior to those published for artificial spinal discs.
  • At 3 and 6 months post-injection of the particles, there were neither adverse local effects nor systemic effects observed.
  • 100% of Axial Rotation was maintained with the ApiFix system
  • 82% of Lateral Bending was maintained with the ApiFix system
  • 60% of Flexion-Extension was maintained with the ApiFix system

1As of February 2020.

268 of the 83 patients with follow-up x-rays.

3Floman Y, El-Hawary R, Lonner BS, Betz RR, Arnin U: Vertebral growth modulation by posterior dynamic deformity correction device in skeletally immature patients with moderate adolescent idiopathic scoliosis. Spine Deformity: Published online August 21, 2020; DOI: https://link.springer.com/article/10.1007/s43390-020-00189-z

4Floman Y, El-Hawary R, Millgram MA, Lonner BS, Betz RR: Surgical management of moderate adolescent idiopathic scoliosis with a fusionless posterior dynamic deformity correction device: interim results with bridging 5–6 disc levels at 2 or more years of follow-up. Journal of Neurosurgery: Published online January 10, 2020; DOI: https://doi.org/10.3171/2019.11.SPINE19827

5Arnin U, El-Hawary R, Betz RR, Lonner BS, Floman Y: Preclinical Bench Testing on a Novel Posterior Dynamic Deformity Correction Device for Scoliosis. Spine Deformity: 7(2019)203-212. DOI: https://doi.org/10.1016/j.jspd.2018.08.010

6Holewijn RM, Kleuver MD, van der Veen AJ, et al: A Novel Spinal Implant for Fusionless Scoliosis Correction: A Biomechanical Analysis of the Motion Preserving Properties of a Posterior Periapical Concave Distraction Device. AO Spine: Published online April 7, 2017; DOI: https://journals.sagepub.com/doi/10.1177/2192568217699377