Potential Risk Factors in Development of the “Halo Sign” in Patients Performed Transpedicular Screw Fixation Through the Posterior Spinal Approach

Öz

It has been shown in literature that a fibrous tissue called "halo sign" in the radiological terminology can develop around the transpedicular screws implanted incompletely and/or incorrectly, which appears after movement of the screw in the cancellous bone. In this retrospective clinical study, 141 patients who underwent posterior spinal instrumentation for thoracic, lumbar or thoracolumbar vertebrae were evaluated using computed tomography (CT) and direct X-rays images for "halo sign" formation which refers in probable failure of spinal instrumentation. Hospital records included in the year 2014-2018 were examined and adult patients who were performed lumbar, thoracal, and thoracolumbar spinal instrumentation via posterior approach due to reasons such as "spine fracture", "spondylosis", "spondylolisthesis" and "intervertebral disc hernia" were included and evaluated in this study. The age and sex of the patients were recorded. Spinal X-ray and spinal CT images obtained during the postoperative follow-up period were examined. Halo sign was seen in 13 patients. Age (p=0.013), number of instrumented vertebrae (p=0.001) and number of transpedicular screws (p<0.001) values were different between the patients with halo sign and patients without halo sign. As a result, it was observed in this study that the formation of the halo sign in posterior spinal instrumentation system could develop in proportion to the number of transpedicular screw and patients' age. It was thought that the halo sign formation was not connected with the parameters called performed laminectomy, gender, inserted intervertebral cage, or vertebral region which were inserted transpedicular screws.

Anahtar Kelimeler

• transpedicular screw,spinal instrumentation,halo sign,posterior approach

Potential Risk Factors in Development of the “Halo Sign” in Patients Performed Transpedicular Screw Fixation Through the Posterior Spinal Approach

Öz

Omurgaya doğru şekilde yerleştirilmeyen transpediküler vidaların kemik yapı içerisinde hareketine ikincil olarak vidaların etrafında ortaya çıkabilen fibröz dokuya radyolojik terminolojide "halo işareti" adı verilmektedir. Bu retrospektif klinik çalışmada, torasik, lomber veya torakolomber vertebra için posterior spinal enstrümantasyon yapılan 141 hasta incelendi ve bu hastalardaki spinal enstrümantasyonun muhtemel başarısızlığını ortaya koyan "halo işareti" oluşumu bilgisayarlı tomografi (BT) ve direkt grafi görüntüleri kullanılarak değerlendirildi. Bu klinik çalışmada 2014-2018 yıllarına ait hastane kayıtları incelenerek  "omurga kırığı", "spondiloz", "spondilolistez" ve “intervertebral disk hernisi”  gibi nedenlerle posterior yaklaşımla lomber, torakal ve torakolomber spinal enstrümantasyon uygulanan yetişkin hastalar çalışmaya dahil edildi. Hastaların omurgaları, ameliyat sonrası takip döneminde elde edilen direkt grafi görüntüleri ve BT görüntüleri kullanılarak değerlendirildi.  Bulgular: 13 hastada halo belirtisi görüldü. Halo işareti olan ve halo işareti olmayan hastalar arasında yaş (p = 0.013), vida kullanılan omurga sayısı (p = 0.001) ve transpediküler vida sayısı (p <0.001) değerleri farklıydı. Bu çalışmanın sonucunda, posterior spinal enstrümantasyon sisteminde halo işaretinin oluşumunun transpediküler vida sayısı ve hasta yaşı ile orantılı olarak gelişebileceği gözlendi. Halo işareti oluşumunda “laminektomi” uygulanmasının, “intervertebral kafes” uygulanmasının, cinsiyetin veya “transpediküler vidanın uygulandığı omurga seviyesi”nin etkili olmadığı düşünüldü.

Anahtar Kelimeler

• transpediküler vida,spinal enstrümentasyon,halo işareti,posterior yaklaşım

Kaynakça

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