TY - JOUR
T1 - Application of laminar screws to posterior fusion of cervical spine
T2 - Measurement of the cervical vertebral arch diameter with a navigation system
AU - Nakanishi, Kazuo
AU - Tanaka, Masato
AU - Sugimoto, Yoshihisa
AU - Misawa, Haruo
AU - Takigawa, Tomoyuki
AU - Fujiwara, Kazuo
AU - Nishida, Keiichiro
AU - Ozaki, Toshifumi
PY - 2008/3
Y1 - 2008/3
N2 - STUDY DESIGN. Morphometric analysis. OBJECTIVE. For safe and solid fixation, it is necessary to measure the diameter of the vertebral arch to ascertain whether or not screws can be used and if so, the appropriate size of screws to be used. SUMMARY OF BACKGROUND DATA. Cervical pedicle screws are the most biomechanically stable screws. However, their use carries a high risk of neurovascular complications during screw insertion. In 2004, a new method to avoid such vertebral artery injuries was reported by insertion of screws with crosswise to the lamina of C2. For safe and solid fixation, it is necessary to measure the diameter of the vertebral arch to ascertain whether or not screws can be used and if so, the appropriate size of screws to be used. There is no report of the diameter of the vertebral arch by a navigation system. METHODS. Morphometric analysis was performed on 42 patients who had undergone a CT scan of the cervical spine for either surgery or diagnostic purposes. To examine the possibilities to insert laminar screws, the diameter of the vertebral arch was measured using a navigation system. RESULTS. The diameter of the vertebral arch in C2 was the largest in the cervical spine, individual differences ranging between 0.8 and 8.4 mm. In C2, insertion of screws with a diameter of 3 mm was possible in 80% of males and 63% of females. As for screws with a diameter of 4 mm, insertion was possible in 50% of the males and 24% of the females in C2. In C2, gender had a significant effect, but left-right differences and height did not. CONCLUSION. Laminar screws are useful as they can prevent vascular injuries, but a preoperative evaluation is necessary.
AB - STUDY DESIGN. Morphometric analysis. OBJECTIVE. For safe and solid fixation, it is necessary to measure the diameter of the vertebral arch to ascertain whether or not screws can be used and if so, the appropriate size of screws to be used. SUMMARY OF BACKGROUND DATA. Cervical pedicle screws are the most biomechanically stable screws. However, their use carries a high risk of neurovascular complications during screw insertion. In 2004, a new method to avoid such vertebral artery injuries was reported by insertion of screws with crosswise to the lamina of C2. For safe and solid fixation, it is necessary to measure the diameter of the vertebral arch to ascertain whether or not screws can be used and if so, the appropriate size of screws to be used. There is no report of the diameter of the vertebral arch by a navigation system. METHODS. Morphometric analysis was performed on 42 patients who had undergone a CT scan of the cervical spine for either surgery or diagnostic purposes. To examine the possibilities to insert laminar screws, the diameter of the vertebral arch was measured using a navigation system. RESULTS. The diameter of the vertebral arch in C2 was the largest in the cervical spine, individual differences ranging between 0.8 and 8.4 mm. In C2, insertion of screws with a diameter of 3 mm was possible in 80% of males and 63% of females. As for screws with a diameter of 4 mm, insertion was possible in 50% of the males and 24% of the females in C2. In C2, gender had a significant effect, but left-right differences and height did not. CONCLUSION. Laminar screws are useful as they can prevent vascular injuries, but a preoperative evaluation is necessary.
KW - Laminar screw
KW - Lateral mass screw
KW - Neurovascular complications
KW - Pedicle screw
KW - Transarticular screw
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U2 - 10.1097/BRS.0b013e318166aa76
DO - 10.1097/BRS.0b013e318166aa76
M3 - Article
C2 - 18344855
AN - SCOPUS:41349107389
VL - 33
SP - 620
EP - 623
JO - Spine
JF - Spine
SN - 0362-2436
IS - 6
ER -