Pull-out strength evaluation of cement augmented iliac screws in osteoporotic spino-pelvic fixation

Ludwig Oberkircher; Adrian Masaeli; Juliana Hack; Jens Figiel; Christopher Bliemel; Steffen Ruchholtz; Antonio Krüger

doi:10.1016/j.otsr.2021.102945

Pull-out strength evaluation of cement augmented iliac screws in osteoporotic spino-pelvic fixation

Orthop Traumatol Surg Res. 2021 Nov;107(7):102945. doi: 10.1016/j.otsr.2021.102945. Epub 2021 Apr 22.

Authors

Ludwig Oberkircher¹, Adrian Masaeli², Juliana Hack², Jens Figiel³, Christopher Bliemel², Steffen Ruchholtz², Antonio Krüger⁴

Affiliations

¹ Philipps University Marburg, Center for Orthopaedics and Trauma Surgery, University Hospital Giessen and Marburg, Location Marburg, Baldingerstrasse, 35037 Marburg, Germany. Electronic address: oberkirc@med.uni-marburg.de.
² Philipps University Marburg, Center for Orthopaedics and Trauma Surgery, University Hospital Giessen and Marburg, Location Marburg, Baldingerstrasse, 35037 Marburg, Germany.
³ Department of diagnostic and interventional radiology, Philipps University Marburg, University Hospital Giessen and Marburg, Location Marburg, Baldingerstrasse, 35037 Marburg, Germany.
⁴ Department of trauma surgery, orthopaedics, spine surgery and pediatric trauma surgery, Asklepios Hospital Lich, Goethestrasse 4, 35423 Lich, Germany.

PMID: 33895387
DOI: 10.1016/j.otsr.2021.102945

Abstract

Introduction: Spino-pelvic fixation has been widely accepted for surgical treatment of sacral tumor, scoliosis surgery and pelvic fractures. Cement augmentation of screws is an option to improve implant stability in osteoporotic bone quality. Aim of the present study is to compare iliac screw fixation without cement fixation and two cement application options in a biomechanical testing.

Hypothesis: Cement augmentation of iliac screws leads to superior pull-out strength.

Material and methods: Thirty female and osteoporotic human iliac bones were used. Three operation treatment groups were generated: Screw fixation (cannulated screws) without cement augmentation [Operation treatment (OT) A], screw fixation with cement augmentation before screw placement (cannulated screws) (OT B) and screw fixation with perforated screws and cement augmentation after screw placement (OTC). Pull-out tests were performed with a rate of 6mm/min. A load versus displacement curve was generated. Maximum pull-out force (N) was measured in the load-displacement curve.

Results: Paired group 1 (OT A vs. OT B): Screw fixation without cement augmentation: 592.6N±335.07 and screw fixation with cement augmentation before screw placement: 996N±287.43 (p=0.0042). Paired group 2 (OT A vs. OT C): screw fixation without cement augmentation: 716.2N±385.86 and fenestrated screw fixation with cement augmentation after screw placement: 1324.88N±398.76 (p=0.0489). Paired group 3 (OT B vs. OT C): Screw fixation with cement augmentation before screw placement: 1077.2±486.66 and fenestrated screw fixation with cement augmentation after screw placement: 1298.2N±726.19 (p=0.3286).

Discussion: Regarding iliac screw fixation for spino-pelvic ostesynthesis in osteoporotic bone, cement augmentation is significantly superior to solid iliac screw fixation respecting pull-out-strength. Nevertheless, further biomechanical studies are needed to verify these findings.

Level of evidence: Not applicable; biomechanical cadaver study.

Keywords: Biomechanical; Cement; Fracture; Iliac screw; Pelvis; Spino-pelvic fixation.

MeSH terms

Biomechanical Phenomena
Bone Cements*
Bone Screws
Cadaver
Female
Humans
Ilium / surgery
Osteoporotic Fractures* / diagnostic imaging
Osteoporotic Fractures* / surgery
Pelvis

Substances

Bone Cements