T Karius1,1, C Deborre1,1, D C Wirtz1, C Burger1, A Prescher2, A Fölsch3, K Kabir1, R Pflugmacher1, H Goost4. 1. Department of Orthopaedics and Trauma Surgery, University Hospital Bonn, Bonn, Germany. 2. Institute of Anatomy, University Hospital RWTH Aachen, Aachen, Germany. 3. Department of Orthopaedics, University Hospital Marburg, Marburg, Germany. 4. Department of Orthopaedics and Trauma Surgery, Hospital Wermelskirchen, Wermelskirchen, Germany.
Abstract
INTRODUCTION: PMMA-augmentation of pedicle screws strengthens the bone-screw-interface reducing cut-out risk. Injection of fluid cement bears a higher risk of extravasation, with difficulty of application because of inconsistent viscosity and limited injection time. OBJECTIVE: To test a new method of cement augmentation of pedicle screws using radiofrequency-activated PMMA, which is suspected to be easier to apply and have less extravasations. METHODS: Twenty-seven fresh-frozen human cadaver lumbar spines were divided into 18 osteoporotic (BMD ≤ 0.8 g/cm2) and 9 non-osteoporotic (BMD > 0.8 g/cm2) vertebral bodies. Bipedicular cannulated pedicle screws were implanted into the vertebral bodies; right screws were augmented with ultra-high viscosity PMMA, whereas un-cemented left pedicle screws served as negative controls. Cement distribution was controlled with fluoroscopy and CT scans. Axial pullout forces of the screws were measured with a material testing machine, and results were analyzed statistically. RESULTS: Fluoroscopy and CT scans showed that in all cases an adequately big cement depot with homogenous form and no signs of extravasation was injected. Pullout forces showed significant differences (p < 0.001) between the augmented and non-augmented pedicle screws for bone densities below 0.8 g/cm2 (661.9 N ± 439) and over 0.8 g/cm2 (744.9 N ± 415). CONCLUSIONS: Pullout-forces were significantly increased in osteoporotic as well as in non-osteoporotic vertebral bodies without a significant difference between these groups using this standardized, simple procedure with increased control and less complications like extravasation.
INTRODUCTION:PMMA-augmentation of pedicle screws strengthens the bone-screw-interface reducing cut-out risk. Injection of fluid cement bears a higher risk of extravasation, with difficulty of application because of inconsistent viscosity and limited injection time. OBJECTIVE: To test a new method of cement augmentation of pedicle screws using radiofrequency-activated PMMA, which is suspected to be easier to apply and have less extravasations. METHODS: Twenty-seven fresh-frozen human cadaver lumbar spines were divided into 18 osteoporotic (BMD ≤ 0.8 g/cm2) and 9 non-osteoporotic (BMD > 0.8 g/cm2) vertebral bodies. Bipedicular cannulated pedicle screws were implanted into the vertebral bodies; right screws were augmented with ultra-high viscosity PMMA, whereas un-cemented left pedicle screws served as negative controls. Cement distribution was controlled with fluoroscopy and CT scans. Axial pullout forces of the screws were measured with a material testing machine, and results were analyzed statistically. RESULTS: Fluoroscopy and CT scans showed that in all cases an adequately big cement depot with homogenous form and no signs of extravasation was injected. Pullout forces showed significant differences (p < 0.001) between the augmented and non-augmented pedicle screws for bone densities below 0.8 g/cm2 (661.9 N ± 439) and over 0.8 g/cm2 (744.9 N ± 415). CONCLUSIONS: Pullout-forces were significantly increased in osteoporotic as well as in non-osteoporotic vertebral bodies without a significant difference between these groups using this standardized, simple procedure with increased control and less complications like extravasation.
Authors: Lukas Weiser; Gerd Huber; Kay Sellenschloh; Lennart Viezens; Klaus Püschel; Michael M Morlock; Wolfgang Lehmann Journal: Eur Spine J Date: 2017-04-08 Impact factor: 3.134
Authors: Ulrich J Spiegl; Martin Weidling; Viktoria Nitsch; Robin Heilmann; Martin Heilemann; Toni Wendler; Stefan Schleifenbaum; Martin Reinhardt; Christoph-E Heyde Journal: Sci Rep Date: 2021-12-10 Impact factor: 4.379