Pedikül Vidaları İçin PLA Malzeme Kullanımının Mukavemet Açısından Değerlendirilmesi

Year 2021, Volume: 21 Issue: 4, 996 - 1004, 31.08.2021

Talip Çelik , Çağatay Taşdemirci , İbrahim Mutlu , Arif Özkan

https://doi.org/10.35414/akufemubid.892317

Abstract

Omurga sorunlarında sıklıkla pedikül vida ve rod sistemleri kullanılır. Bu sistemlerin en büyük sorunları vida kırılması ve vida gevşemesidir. Vida ve rod malzemesi olarak halihazırda metalik implantlar kullanılmaktadır ve metalik implantların elastik modüllerinin yüksek olması sebebi ile kemiğe yük aktarımında sıkıntılar oluşabilmektedir. Bu çalışmada, metalik implantlara göre elastiklik modülü daha düşük olan ve son zamanlarda kullanımı artan Polilaktik Asit (PLA) malzemesi ve bu malzemeden oluşturulan Polilaktik Asit/Hidroksiapatit (PLA/HA) kompozit malzemesinin pedikül vidalarında kullanılabilirliği mukavemet yönünden değerlendirilmiştir. Bu amaçla sonlu elemanlar yöntemi kullanılmıştır. T9 omurga modeli MIMICS yazılımı ile oluşturulmuş ve vida-rod modelleri ile ameliyat prosedürüne uygun olarak bilgisayar ortamında birleştirilmiştir. Sonlu elemanlar analizi için pedikül vida malzemeleri Ti6Al4V, PLA ve PLA/HA malzemeleri seçilmiştir. Ayrıca, pedikül vida modeli üzerinde tasarım değiştirerek iki farklı model daha analize katılmıştır. Yapılan 5 farklı analiz sonuçları karşılaştırılmış ve en uygun pedikül malzemesi/tasarımı belirlenmiştir. Sonuç olarak, PLA/HA kompozit malzeme kullanımı yeterli mukavemete ve rijitliğe sahip olmuştur. Ayrıca, vida tasarım değişikliği ile PLA malzemesi pedikül vidalar için kullanılabilir.

Keywords

Pedikül vidası, Vida rod sistemi, PLA, PLA/HA, Sonlu elemanlar analizi

Evaluation of the Use of PLA Material for Pedicle Screws in Terms of Strength

Abstract

Pedicle screw and rod systems are frequently used in spinal diseases. The biggest problems of these systems are screw failure and screw loosening. Metal implants are currently used as screw and rod materials, and problems may occur in load transfer to the bone due to the high elastic modulus of metallic implants. In this study, the use of the Polylactic Acid (PLA) material, which has a lower elasticity module compared to metallic implants and has recently increased, and the Polylactic Acid / Hydroxyapatite (PLA / HA) composite material formed from this material, in pedicle screws were evaluated in terms of strength. For this purpose, the finite element method has been used. The T9 spine model was created with MIMICS software and assembled with screw-rod models in a computer environment in accordance with the surgical procedure. Pedicle screw materials Ti6Al4V, PLA, and PLA / HA materials were selected for finite element analysis. In addition, two different models were included in the analysis by changing the design of the pedicle screw model. The results of 5 different analyzes were compared and the most suitable pedicle material/design was determined. As a result, the use of PLA/HA composite material has had sufficient strength and rigidity. Also, with the screw design change, PLA material can be used for pedicle screws.

Keywords

Pedicle screw, Screw rod system, PLA, PLA/HA, Finite element analysis

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