Turkish Neurosurgery
What is the effect of pedicle screw reinsertion through the same trajectory on pullout strength?
Orhan Kalemci2, Ceren Kizmazoglu2, Safak Ozyoruk3, Inan Uzunoglu1, Bugra Husemoglu4, Murat Atar5, Hasan Emre Aydin6, Ahmet Karakasli7
1Katip Celebi Unıversity Ataturk Training and Research Hospital, Department of Neurosurgery, İzmir,
2Dokuz Eylul University, Department of Neurosurgery, İzmir,
3Private OFM Antalya Hospital , Department of Neurosurgery, Antalya,
4Dokuz Eylül University Heath Science Institude, Department of Biomechanics, İzmir,
5Abdulhamid Han Training and Research Hospital,, Department of Neurosurgery, Istanbul,
6Kutahya Health Science University, Department of Neurosurgery, Kutahya,
7Dokuz Eylul University, Department of Orthopedics and Traumatology, İzmir,
DOI: 10.5137/1019-5149.JTN.35526-21.3
Aim:To investigate the pullout strength of a pedicle screw reinserted through the same trajectory.Material and Methods:Fifty freshly frozen lamb L4 vertebrae were divided into the following five groups: Group 1, insertion of a 5-mm pedicle screw; Group 2, insertion of a 5-mm pedicle screw followed by the removal and reinsertion of the same screw after control; Group 3, insertion of a 5-mm pedicle screw followed by the removal and reinsertion of a 5.5-mm screw after control; Group 4, insertion of a 5.5-mm pedicle screw; and Group 5, insertion of a 5.5-mm pedicle screw followed by the removal and reinsertion of the same screw after control. Pedicle screws were inserted into the right pedicles, and axial pullout testing was performed at a rate of 5 mm/min. All data were recorded. A load-displacement curve was used to obtain the peak value of the pullout strength for all specimens.Results:The mean pullout strengths were 1086.22 N for Group 1, 1043.32 N for Group 2, 1039.18 N for Group 3, 1199.10 N for Group 4, and 1131.68 N for Group 5. There was no significant difference between the groups (p > 0.05).Conclusion:Perioperative reinsertion of the same screw or a pedicle screw 0.5 larger in diameter through the same trajectory after the control of the screw trajectory did not affect the pullout strength of the screw.
Corresponding author : Orhan Kalemci