PDF
ePub
Citation
Print
Abstract
Objective
This retrospective study was conducted to analyze the novice neurosurgeon's experience of cervical pedicle screw placement by using the technique with direct exposure of pedicle via para-articular mini-laminotomy.
Methods
Fifteen sawbone models of subaxial spine were used (124 pedicles) to evaluate efficacy of repetitive training improving accuracy of cervical pedicle screw insertion. After that, we retrospectively reviewed 9 consecutive patients presented with traumatic cervical lesion. A total 38 cervical pedicle screws had been inserted. We analyzed the direction and grade of pedicle perforation on the postoperative computed tomography scan, and learning curve by using sawbone model.
Results
In sawbone model group, the correct position was found in 102 (82.3%) screws, and the incorrect position in 22 (17.7%) screws. The incidence of incorrect screw position was 26.9% in the initial 9 sawbone model, and 0% after that. Among the 38 screws inserted in 9 patients, the correct position was found in 36 (94.7%) screws, and the incorrect position in a 2 (5.3%) screw. There was no neurovascular complications related with cervical pedicle screw insertion.
Conclusion
In vitro training to insert pedicle screw by using sawbone models could improve an accuracy of cervical pedicle screw placement by using this technique. Preliminary result revealed that cervical pedicle screw placement would be feasible and provide good clinical results in traumatic cervical lesions.
References
1. Abumi K. Point of view. Spine (Phila Pa 1976). 27:1167. 2002.
2. Abumi K, Itoh H, Taneichi H, Kaneda K. Transpedicular screw fixation for traumatic lesions of the middle and lower cervical spine: description of the techniques and preliminary report. J Spinal Disord. 7:19–28. 1994.
3. Abumi K, Kaneda K. Pedicle screw fixation for nontraumatic lesions of the cervical spine. Spine (Phila Pa 1976). 22:1853–1863. 1997.
4. Abumi K, Shono Y, Ito M, Taneichi H, Kotani Y, Kaneda K. Complications of pedicle screw fixation in reconstructive surgery of the cervical spine. Spine (Phila Pa 1976). 25:962–969. 2000.
5. Abumi K, Shono Y, Taneichi H, Ito M, Kaneda K. Correction of cervical kyphosis using pedicle screw fixation systems. Spine (Phila Pa 1976). 24:2389–2396. 1999.
6. Allen BL Jr, Ferguson RL, Lehmann TR, O'Brien RP. A mechanistic classification of closed, indirect fractures and dislocations of the lower cervical spine. Spine (Phila Pa 1976). 7:1–27. 1982.
7. Ishikawa Y, Kanemura T, Yoshida G, Ito Z, Muramoto A, Ohno S. Clinical accuracy of three-dimensional fluoroscopy-based computer-assisted cervical pedicle screw placement: a retrospective comparative study of conventional versus computer-assisted cervical pedicle screw placement. J Neurosurg Spine. 13:606–611. 2010.
8. Ishikawa Y, Kanemura T, Yoshida G, Matsumoto A, Ito Z, Tauchi R, et al. Intraoperative, full-rotation, three-dimensional image (O-arm)-based navigation system for cervical pedicle screw insertion. J Neurosurg Spine. 15:472–478. 2011.
9. Ito Y, Sugimoto Y, Tomioka M, Hasegawa Y, Nakago K, Yagata Y. Clinical accuracy of 3D fluoroscopy-assisted cervical pedicle screw insertion. J Neurosurg Spine. 9:450–453. 2008.
10. Ito Z, Higashino K, Kato S, Kim SS, Wong E, Yoshioka K, et al. Pedicle Screws Can be 4 Times Stronger Than Lateral Mass Screws for Insertion in the Midcervical Spine: A Biomechanical Study on Strength of Fixation. J Spinal Disord Tech, 2012 Feb 27 [Epub ahead of print].
11. Jo DJ, Seo EM, Kim KT, Kim SM, Lee SH. Cervical pedicle screw insertion using the technique with direct exposure of the pedicle by laminoforaminotomy. J Korean Neurosurg Soc. 52:459–465. 2012.
12. Jones EL, Heller JG, Silcox DH, Hutton WC. Cervical pedicle screws versus lateral mass screws. Anatomic feasibility and biomechanical comparison. Spine (Phila Pa 1976). 22:977–982. 1997.
13. Karaikovic EE, Daubs MD, Madsen RW, Gaines RW Jr. Morphologic characteristics of human cervical pedicles. Spine (Phila Pa 1976). 22:493–500. 1997.
14. Karaikovic EE, Yingsakmongkol W, Gaines RW Jr. Accuracy of cervical pedicle screw placement using the funnel technique. Spine (Phila Pa 1976). 26:2456–2462. 2001.
15. Kotani Y, Abumi K, Ito M, Minami A. Improved accuracy of computer-assisted cervical pedicle screw insertion. J Neurosurg 99 (3 Suppl):257–263. 2003.
16. Kotani Y, Cunningham BW, Abumi K, McAfee PC. Biomechanical analysis of cervical stabilization systems. An assessment of transpedicular screw fixation in the cervical spine. Spine (Phila Pa 1976). 19:2529–2539. 1994.
17. Kothe R, Rüther W, Schneider E, Linke B. Biomechanical analysis of transpedicular screw fixation in the subaxial cervical spine. Spine (Phila Pa 1976). 29:1869–1875. 2004.
18. Kotil K, Akçetin MA, Savas Y. Neurovascular complications of cervical pedicle screw fixation. J Clin Neurosci. 19:546–551. 2012.
19. Lee SH, Kim KT, Abumi K, Suk KS, Lee JH, Park KJ. Cervical pedicle screw placement using the “key slot technique”: the feasibility and learning curve. J Spinal Disord Tech. 25:415–421. 2012.
20. Neo M, Sakamoto T, Fujibayashi S, Nakamura T. The clinical risk of vertebral artery injury from cervical pedicle screws inserted in degenerative vertebrae. Spine (Phila Pa 1976). 30:2800–2805. 2005.
21. Panjabi MM, Duranceau J, Goel V, Oxland T, Takata K. Cervical human vertebrae. Quantitative three-dimensional anatomy of the middle and lower regions. Spine (Phila Pa 1976). 16:861–869. 1991.
22. Panjabi MM, Shin EK, Chen NC, Wang JL. Internal morphology of human cervical pedicles. Spine (Phila Pa 1976). 25:1197–1205. 2000.
23. Rajasekaran S, Kanna PR, Shetty AP. Safety of cervical pedicle screw insertion in children: a clinicoradiological evaluation of computer-assisted insertion of 51 cervical pedicle screws including 28 subaxial pedicle screws in 16 children. Spine (Phila Pa 1976). 37:E216–E223. 2012.
24. Rath SA, Moszko S, Schäffner PM, Cantone G, Braun V, Richter HP, et al. Accuracy of pedicle screw insertion in the cervical spine for internal fixation using frameless stereotactic guidance. J Neurosurg Spine. 8:237–245. 2008.
25. Richter M, Cakir B, Schmidt R. Cervical pedicle screws: conventional versus computer-assisted placement of cannulated screws. Spine (Phila Pa 1976). 30:2280–2287. 2005.
26. Scheufler KM, Franke J, Eckardt A, Dohmen H. Accuracy of imageguided pedicle screw placement using intraoperative computed tomography-based navigation with automated referencing, part I: cervicothoracic spine. Neurosurgery. 69:782–795. ; discussion 795,. 2011.
27. Tauchi R, Imagama S, Sakai Y, Ito Z, Ando K, Muramoto A, et al. The correlation between cervical range of motion and misplacement of cervical pedicle screws during cervical posterior spinal fixation surgery using a CT-based navigation system. Eur Spine J. 22:1504–1508. 2013.
28. Tofuku K, Koga H, Komiya S. Cervical pedicle screw insertion using a gutter entry point at the transitional area between the lateral mass and lamina. Eur Spine J. 21:353–358. 2012.
29. Yoshimoto H, Sato S, Hyakumachi T, Yanagibashi Y, Masuda T. Spinal reconstruction using a cervical pedicle screw system. Clin Orthop Relat Res:111–119. 2005.
30. Yukawa Y, Kato F, Yoshihara H, Yanase M, Ito K. Cervical pedicle screw fixation in 100 cases of unstable cervical injuries: pedicle axis views obtained using fluoroscopy. J Neurosurg Spine. 5:488–493. 2006.
FIGURE 1.
Preoperative axial CT images (A: left-sawbone, right-patient) showing the diameter (arrow) and the convergence angle (θ) of the pedicle, and 3D reconstruction image of saw-bone (B) revealing the caudal angle between superior margin of pedicle (solid line) and imaginary line on which pedicle screw would be placed (dot line).
FIGURE 2.
2.5 mm diamond burr is used to perform para-articular mini-laminotomy (A). The laminotomy provides direct visualization of medial and superior wall of the pedicle (B). Burr is used to remove the outer cortex of the lateral mass over the entry point. The caudal angle (between solid and dot line) should be considered to determine the trajectory (C), and convergence angle should be determined under the direct visualization of the pedicle (D). P: pedicle, IF: inferior facet.
FIGURE 3.
During the screw insertion, the pedicle should be visualized though the whole procedure (A). After the subperiosteal dissection of the pedicle, medial and superior wall of the pedicle (B, arrow) remained to be exposed by using a microdissector.
FIGURE 4.
Grading system of the pedicle perforation. Grade 0: the screw is located within the pedicle (A). Grade 1: perforation less than 25% of the screw diameter (B). Grade 2: 25–50% of the screw diameter (C). Grade 3: over 50% (D).
FIGURE 5.
During the procedure, pedicle perforation (arrow) is directly visualized on sawbone model (A), and post-procedural CT of sa bone model shows grade 1 perforation (B).
FIGURE 6.
The number of total screws and screws showed incorrect position (>grade 2 perforation) in 15 consecutive cases of sawbone model. After initial 9 cases of sawbone model, there was no incorrect screw insertion.
FIGURE 7.
Post-operative axial CT showing grade 3 perforation (A). Trajectory of the pedicle screw placement was indicated with dot lines. Due to an inadequate laminotomy, convergence angle underestimated along the lateral margin of the foraminotomy site (solid line). About 1–2 mm drilling of medial wall of lateral mass might be helpful to fully expose a proximal segment of pedicle (B).
TABLE 1.
Results of pedicle screw placement at each level
XML Download