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Original research
The 'armed concrete' approach: stent-screw-assisted internal fixation (SAIF) reconstructs and internally fixates the most severe osteoporotic vertebral fractures
  1. Daniela Distefano1,
  2. Pietro Scarone2,
  3. Maurizio Isalberti1,
  4. Luigi La Barbera3,4,5,
  5. Tomaso Villa4,
  6. Giuseppe Bonaldi6,
  7. Joshua A Hirsch7,
  8. Alessandro Cianfoni1,8
  1. 1Department of Neuroradiology, Neurocenter of Southern Switzerland, Lugano, Switzerland
  2. 2Department of Neurosurgery, Neurocenter of Southern Switzerland, Lugano, Switzerland
  3. 3Department of Mechanical Engineering, Polytechnique Montréal, Montreal, Québec, Canada
  4. 4Laboratory of Biological Structure Mechanics, Department of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, Milan, Italy
  5. 5Sainte-Justine Clinical Hospital Center, Montréal, Quebec, Canada
  6. 6Department of Neurosurgery, Casa di Cura Igea, Milano, Lombardia, Italy
  7. 7Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
  8. 8Department of Interventional and Diagnostic Neuroradiology, Inselspital University Hospital Bern, Bern, Switzerland
  1. Correspondence to Dr Daniela Distefano, Department of Neuroradiology, Neurocenter of Southern Switzerland, Lugano, Switzerland; daniela.distefano{at}


Background The treatment of severe osteoporotic vertebral compression fractures (VCFs) with middle-column (MC) involvement, high fragmentation, large cleft and/or pedicular fracture is challenging. Minimally invasive 'stent-screw-assisted internal fixation' (SAIF) can reduce the fracture, reconstruct the vertebral body (VB) and fix it to the posterior elements.

Objective To assess feasibility, safety, technical and clinical outcome of the SAIF technique in patients with severe osteoporotic VCFs.

Methods 80 treated vertebrae were analyzed retrospectively. Severe VCFs were characterized by advanced collapse (Genant grade 3), a high degree of osseous fragmentation (McCormack grade 2 and 3), burst morphology with MC injury, pediculo-somatic junction fracture, and/or large osteonecrotic cleft. VB reconstruction was evaluated on postprocedure radiographs and CT scans by two independent raters. Clinical and radiological follow-ups were performed at 1 and 6 months.

Results SAIF was performed at 28 thoracic and 52 lumbar levels in 73 patients. One transient neurological complication occurred. VB reconstruction was satisfactory in 98.8% of levels (inter-rater reliability 96%, κ=1). Follow-up at 1 month was available for 78/80 levels and at 6 months or later (range 6–24, mean 7.9 months) for 73/80 levels. Significant improvement in the Visual Analog Scale score was noted at 1 and 6 months after treatment (p<0.05). Patients reported global clinical benefit during follow-up (Patient’s Global Impression of Change Scale 5.6±0.9 at 1 month and 6.1±0.9 at 6 months). Fourteen new painful VCFs occurred at different levels in 11 patients during follow-up, treated with vertebral augmentation or SAIF. Target-level stability was maintained in all cases.

Conclusions SAIF is a minimally invasive, safe, and effective treatment for patients with severe osteoporotic VCFs with MC involvement.

  • spine
  • technique
  • stent
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  • Contributors All authors contributed substantially to the conception or design of the presented work. Acquisition of data: DD, AC, PS, MI. Analysis and interpretation of data: all authors. Drafting the article: all authors. Critically revising the article: JAH, AC. Statistical analysis: DD. Study supervision: AC, TV, GB, JAH.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Patient consent for publication Not required.

  • Ethics approval Ethics committee of Canton Ticino (ID 14-136).

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement All data relevant to the study are included in the article or uploaded as supplementary information.

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