Comparison of the Pullout Strength of Different Pedicle Screw Designs and Augmentation Techniques in an Osteoporotic Bone Model
Study DesignMechanical study.PurposeTo compare the pullout strength of different screw designs and augmentation techniques in an osteoporotic bone model.Overview of LiteratureAdequate bone screw pullout strength is a common problem among osteoporotic patients. Various screw designs and augmentation...
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| Format: | Article |
| Language: | English |
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Korean Spine Society
2018-02-01
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| Series: | Asian Spine Journal |
| Subjects: | |
| Online Access: | http://www.asianspinejournal.org/upload/pdf/asj-12-3.pdf |
| _version_ | 1811302368812204032 |
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| author | Gorkem Kiyak Tevfik Balikci Ahmed Majid Heydar Murat Bezer |
| author_facet | Gorkem Kiyak Tevfik Balikci Ahmed Majid Heydar Murat Bezer |
| author_sort | Gorkem Kiyak |
| collection | DOAJ |
| description | Study DesignMechanical study.PurposeTo compare the pullout strength of different screw designs and augmentation techniques in an osteoporotic bone model.Overview of LiteratureAdequate bone screw pullout strength is a common problem among osteoporotic patients. Various screw designs and augmentation techniques have been developed to improve the biomechanical characteristics of the bone–screw interface.MethodsPolyurethane blocks were used to mimic human osteoporotic cancellous bone, and six different screw designs were tested. Five standard and expandable screws without augmentation, eight expandable screws with polymethylmethacrylate (PMMA) or calcium phosphate augmentation, and distal cannulated screws with PMMA and calcium phosphate augmentation were tested. Mechanical tests were performed on 10 unused new screws of each group. Screws with or without augmentation were inserted in a block that was held in a fixture frame, and a longitudinal extraction force was applied to the screw head at a loading rate of 5 mm/min. Maximum load was recorded in a load displacement curve.ResultsThe peak pullout force of all tested screws with or without augmentation was significantly greater than that of the standard pedicle screw. The greatest pullout force was observed with 40-mm expandable pedicle screws with four fins and PMMA augmentation. Augmented distal cannulated screws did not have a greater peak pullout force than nonaugmented expandable screws. PMMA augmentation provided a greater peak pullout force than calcium phosphate augmentation.ConclusionsExpandable pedicle screws had greater peak pullout forces than standard pedicle screws and had the advantage of augmentation with either PMMA or calcium phosphate cement. Although calcium phosphate cement is biodegradable, osteoconductive, and nonexothermic, PMMA provided a significantly greater peak pullout force. PMMA-augmented expandable 40-mm four-fin pedicle screws had the greatest peak pullout force. |
| first_indexed | 2024-04-13T07:26:52Z |
| format | Article |
| id | doaj.art-5501080057344bf7b8b0e9f986020686 |
| institution | Directory Open Access Journal |
| issn | 1976-1902 1976-7846 |
| language | English |
| last_indexed | 2024-04-13T07:26:52Z |
| publishDate | 2018-02-01 |
| publisher | Korean Spine Society |
| record_format | Article |
| series | Asian Spine Journal |
| spelling | doaj.art-5501080057344bf7b8b0e9f9860206862022-12-22T02:56:27ZengKorean Spine SocietyAsian Spine Journal1976-19021976-78462018-02-0112131110.4184/asj.2018.12.1.3351Comparison of the Pullout Strength of Different Pedicle Screw Designs and Augmentation Techniques in an Osteoporotic Bone ModelGorkem Kiyak0Tevfik Balikci1Ahmed Majid Heydar2Murat Bezer3Department of Orthopaedic Surgery, Academic Hospital, Istanbul, Turkey.Department of Orthopaedic Surgery, Medistate Hospital Kavacık, Istanbul, Turkey.Department of Orthopaedic Surgery, Marmara University Faculty of Medicine, Istanbul, Turkey.Department of Orthopaedic Surgery, Marmara University Faculty of Medicine, Istanbul, Turkey.Study DesignMechanical study.PurposeTo compare the pullout strength of different screw designs and augmentation techniques in an osteoporotic bone model.Overview of LiteratureAdequate bone screw pullout strength is a common problem among osteoporotic patients. Various screw designs and augmentation techniques have been developed to improve the biomechanical characteristics of the bone–screw interface.MethodsPolyurethane blocks were used to mimic human osteoporotic cancellous bone, and six different screw designs were tested. Five standard and expandable screws without augmentation, eight expandable screws with polymethylmethacrylate (PMMA) or calcium phosphate augmentation, and distal cannulated screws with PMMA and calcium phosphate augmentation were tested. Mechanical tests were performed on 10 unused new screws of each group. Screws with or without augmentation were inserted in a block that was held in a fixture frame, and a longitudinal extraction force was applied to the screw head at a loading rate of 5 mm/min. Maximum load was recorded in a load displacement curve.ResultsThe peak pullout force of all tested screws with or without augmentation was significantly greater than that of the standard pedicle screw. The greatest pullout force was observed with 40-mm expandable pedicle screws with four fins and PMMA augmentation. Augmented distal cannulated screws did not have a greater peak pullout force than nonaugmented expandable screws. PMMA augmentation provided a greater peak pullout force than calcium phosphate augmentation.ConclusionsExpandable pedicle screws had greater peak pullout forces than standard pedicle screws and had the advantage of augmentation with either PMMA or calcium phosphate cement. Although calcium phosphate cement is biodegradable, osteoconductive, and nonexothermic, PMMA provided a significantly greater peak pullout force. PMMA-augmented expandable 40-mm four-fin pedicle screws had the greatest peak pullout force.http://www.asianspinejournal.org/upload/pdf/asj-12-3.pdfScrewPedicleExpandableOsteoporosisAugmentation |
| spellingShingle | Gorkem Kiyak Tevfik Balikci Ahmed Majid Heydar Murat Bezer Comparison of the Pullout Strength of Different Pedicle Screw Designs and Augmentation Techniques in an Osteoporotic Bone Model Asian Spine Journal Screw Pedicle Expandable Osteoporosis Augmentation |
| title | Comparison of the Pullout Strength of Different Pedicle Screw Designs and Augmentation Techniques in an Osteoporotic Bone Model |
| title_full | Comparison of the Pullout Strength of Different Pedicle Screw Designs and Augmentation Techniques in an Osteoporotic Bone Model |
| title_fullStr | Comparison of the Pullout Strength of Different Pedicle Screw Designs and Augmentation Techniques in an Osteoporotic Bone Model |
| title_full_unstemmed | Comparison of the Pullout Strength of Different Pedicle Screw Designs and Augmentation Techniques in an Osteoporotic Bone Model |
| title_short | Comparison of the Pullout Strength of Different Pedicle Screw Designs and Augmentation Techniques in an Osteoporotic Bone Model |
| title_sort | comparison of the pullout strength of different pedicle screw designs and augmentation techniques in an osteoporotic bone model |
| topic | Screw Pedicle Expandable Osteoporosis Augmentation |
| url | http://www.asianspinejournal.org/upload/pdf/asj-12-3.pdf |
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