Influence of reduced tip-apex distance on helical blade fixation-a biomechanical study
| Autor: | Ronald Schwyn, Boyko Gueorguiev, Gunther O. Hofmann, Matthias Knobe, Mark Lenz, Ladina Hofmann-Fliri, Jana Schwinn, Heike Kielstein, Kajetan Klos |
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| Rok vydání: | 2018 |
| Předmět: |
Fixation stability
Male Radiography 0206 medical engineering Bone Screws Tip apex distance 02 engineering and technology 03 medical and health sciences 0302 clinical medicine Medicine Humans Orthopedics and Sports Medicine Helical blade Fixation (histology) Aged 030203 arthritis & rheumatology Orthodontics Bone mineral Aged 80 and over business.industry Hip Fractures Middle Aged 020601 biomedical engineering Biomechanical Phenomena medicine.anatomical_structure Female Implant business Cancellous bone |
| Zdroj: | Journal of orthopaedic research : official publication of the Orthopaedic Research Society. 37(3) |
| ISSN: | 1554-527X |
| Popis: | Migration profile of helical blades differs from conventional screw design. Tip-apex distance (TAD) greater than 25 mm is associated with early failure in hip screws. This study investigates the effect of a reduced TAD on helical blade fixation. Six pairs of human femoral heads were used. Bone mineral density (BMD) was determined by pQCT. Local bone quality was evaluated by breakaway torque. Helical blades were implanted with TAD of 20 mm (normal) and 6 mm (reduced). Specimens were cyclically tested under progressively increasing physiologic loading at 2 Hz with starting peak force of 1'000N, increasing by 0.1N/cycle. Implant migration was monitored by radiographs every 250 cycles. Paired Student's t-test and Spearman rank correlation coefficient were used for statistical evaluation (p |
| Databáze: | OpenAIRE |
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