Different pedicle osteosynthesis for thoracolumbar vertebral fractures in elderly patients

Pedicle screws' stability, especially in osteoporotic fractures, is a really problem for spinal surgeons. Nowadays, little is known about the influence of different screw types and amount of cement applied. This single-center retrospective observational study has the aim of evaluating the middle- to long-term mechanical performances of different types of screws in elderly patients with thoracolumbar fractures.

A total of 91 patients (37 males and 54 females), treated between 2011 and 2016, affected by somatic osteoporotic fractures aged over 65 years were treated. We divided patients into three different populations: solid screws, cannulated screws and cannulated screws augmented with poly methyl methacrylate cement (PMMA). Patients were radiologically evaluated with X-rays in pre- and post-surgery and at the follow-up (FU). Clinical evaluations were made with VAS and Oswestry Disability Index.

A total of 636 screws were implanted (222 pedicle screws, 190 cannulated and 224 cannulated screws with PMMA augmentation). At FU, we found significative differences between populations in terms of mechanical performances. We founded five cases of loosening; these were reported in solid screws group and in cannulated screws one. No mechanical failures were reported in cannulated screws with augmentation of PMMA. No rods breakage cases were reported.

All stabilization methods showed good clinical results, but cannulated screws augmented with PMMA seem to provide better implant stability with the lowest rate of loosening. These slides can be retrieved under Electronic Supplementary Material.