CEM ZEKİ ESENYEL, Ercan OLCAY, Erdoğan MERİH, Rıdvan YEŞİLTEPE, TURGUT GÜLMEZ, AYHAN NEDİM KARA

Korpektomi yapılan vertebra modellerinde korpektomi yapılmış vertebranın transpediküler fiksasyonunun stabiliteye etkisi: Biyomekanik çalışma

Amaç: Posterior stabilizasyona ek olarak vertebranın transpediküler vida ile tespitinin stabiliteye katkısı olup olmadığı araştırıldı. Çalışma planı: Üç tane hareketli segment içeren 10 adet taze lomber dana vertebrasında ortadaki segmente anterior korpektomi yapıldı. Tüm örneklerde, korpektomi yapılan seviyenin bir altındaki ve bir üstündeki vertebraların pediküllerine birer adet transpediküler vida gönderilerek rodlar aracılığı ile posterior stabilizasyon yapıldı. Bir grup örnekte (n=5) ise ek olarak korpektomi yapılan vertebralara da transpediküler vidalar uygulandı. Her iki gruba, aksiyel yükler uygulanarak örneklerin stabilitesi test edildi. Sonuçlar Mann-Whitney U-Wilcoxon rank sum W testi ile istatistiksel olarak değerlendirildi. Sonuçlar: Korpektomi yapılan seviyedeki ilave transpediküler vida fiksasyonunun stabiliteye ek bir katkısı olmadığı ve hatta test esnasında anterior kolon desteği olmadığı için bu vertebraların pediküllerinde vidaların manevale etkisi ile kolayca kırık oluştuğu gözlendi. Çıkarımlar: Çalışmamızda örnek sayısı az olduğundan ve tek bir yüklenme kuvvetine bakıldığından dolayı, ilaveten fleksiyon, ekstansiyon, laterale eğilme ve torsiyonel kuvvetlerin de değerlendirilerek sonuçların klinik çalışmalarla desteklenmesi yararlı olacaktır.

Anahtar Kelimeler:

Biyomekanik, Hastalık modelleri, hayvan, İnternal fiksatörler, Lumbar omurga, Omurga, Kemik vidaları, Stres, mekanik

A biomechanical investigation of the effect of additional transpedicular fixation of the corpectomied vertebrae on stability: A calf spine model

Objectives: To investigate whether an additional transpedicular screw fixation of the injured vertebra would increase the stability of posterior fixation. Methods: Ten fresh calf spine segments, each containing three motion segments, were obtained and anterior corpectomy was performed at the middle vertebra of each specimen. Posterior spinal instrumentation was performed in all specimens. In one group (n=5), screws were placed into the pedicle one level above and below the corpectomy level. In another group (n=5), additional transpedicular fixations were made at the corpectomy level. Stability of both groups was tested using compressive loads. The results were statistically evaluated using Mann-Whitney U-Wilcoxon rank sum W test. Results: The model showed not only that additional screw placement at the injury level did not contribute to the stability of the posterior stabilization of the vertebrae but also that screws applied to the corpectomied vertebra gave rise to additional injury to the pedicles. Conclus ion: Due to small sample size and since only compressive forces were studied, further studies are required on flexion, extension, lateral bending, and torsional forces and the results should be supported by clinical studies.

Keywords:

Biomechanics, Disease Models, Animal, Internal Fixators, Lumbar Vertebrae, Spine, Bone Screws, Stress, Mechanical,

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