CervicalScrew2011
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The document summarizes various surgical techniques for posterior cervical screw placement at different levels of the cervical spine. It describes techniques for C1 lateral mass screws, C1/2 transarticular screws, C2 laminar screws, C2 pedicle screws, C2 pars interarticularis screws, C3-7 lateral mass screws, C3-7 transarticular screws, and C7 laminar screws. For each technique, it provides details on entry point, angle of insertion, length of screw, and any variations in methodology reported in literature.
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CervicalScrew2011
- 1. Surgical techniques of various methods of posterior cervical screw placement Okayama University Hospital Masato Tanaka MD & PhD
- 2. Surgical technique of various methods of posterior cervical screw placement C1 Lateral mass screw Direct insertion (Goel 1994) Translaminar insertion (Tan 2003) Noch insertion (Lee 2006) C1/2 Transarticular screw (Magerl 1987) C2 Laminar screw (Wright 2004) Pars interarticularis screw Pedicle screw (Judet 1962) C3-6 Pedicle screw (Abumi 1997) Lateral mass screw Magerl method (Magerl 1991) Roy-Camille method (Roy-Camille 1972) Transarticular(facet) screw (King 1944) C7 Laminar screw Pedicle screw
- 3. London, St. Paul cathedral Surgical technique of C1 LMS
- 4. Anatomy of C1 & C2 (vessels, nerve, muscle)
- 5. Anatomy of C1 & C2 (Bone) 15mm 13mm Tan 4.6mm (8%<4mm) Lee 4.0mm (14%>5mm) C1 Lamina thickness C1 Lateral mass height Goel AP 20mm Tan AP 30mm ML 18mm
- 6. Three methods of C1 LMS placement Direct insertion (Goel 1994) C2 root & venous problem Translaminar (Tan 2003) C1 root, lamina breakage Notching (Lee&Riew 2006) Ideal method? L/M mid point (lower end) 10 o medial 5-10 o cephalad 2mm 19mm L/M mid point, 1-2 mm above articular surface 15 o medial 15 o cephalad 19mm lateral, 2mm superior 5 o cephalad 0 o medial
- 7. C1 LMS technique (Goel 1994) L=16-18mm Mid point 15 o medial 15 o cephalad
- 8. C1 LMS technique (Tan 2003) 19mm lateral, 2mm superior L=24-28mm Mid point (lamina ½) 5 o cephalad straight
- 9. UK, Stonehenge Surgical technique of C2 laminar screw
- 10. C2 laminar screw (Wright 2004) (Tanaka 2009) The entry point is the junction of C-2 spinous process and lamina on the right, close to the rostral margin of the C-2 lamina. A second screw was placed into the right lamina, with the entry point at the junction of the spinous process and the left lamina, along the caudal margin of the lamina. The length is 30mm . L=26-30mm (Yue 2010) 5-6mm posterior to the post-edge of the spinal canal, angle 50-60 o
- 11. C2 laminar screw (Wright 2004) L=26-30mm 5-6mm 50-60 o
- 12. London, Buckingham palace Surgical technique of C2 pedicle screw
- 13. C2 pedicle screw (Judet 1962) Entry point Mid point of Upper/Lower Axial 40 o Medial Sagittal 30 o cephalad L=24-28mm
- 14. C3-6 pedicle screw (Abumi 1997) Entry point : slightly lateral to the center of the articular mass close to the inferior margin of the inferior articular process of the cranially adjacent vertebra. Insertion angle of the screws : C3 to C7 was intended to be 25 o to 45 o medial to the midline in the transverse plane. 25 o to 45 o (Abumi Spine 1997) L=20-28mm Noch Must be confirmed on CTs. (Karaikovic EE J Spinal Disord, 2000)
- 15. C2 pedicle screw (Judet 1962) L=24-28mm Mid point of upper/lower 40 o medial 30 o cephalad
- 16. Goel method (C1 LMS & C2 Pedicle screw) 15 o medial 15 o cephalad 15 o medial 40 o medial 30 o cephalad
- 17. Chiang Mai S4
- 18. London, Big Ben Surgical technique of C2 pars screw
- 19. C2 pars interarticularis screw L=14-18mm C2 pedicle screw Axial 40 o Sagittal 30 o C2 pars screw Axial 10 o Sagittal 50 o
- 20. C2 pars interarticularis screw 40 o cranial L=14-18mm 10 o Medial Mid point or 4X4mm 4
- 21. London, Tower Bridge Surgical technique of C1/2 Transarticular screw
- 22. C1/2 transarticular screw (Magerl 1987) Entry point M/L mid point 3mm from lower end Axial 10 o Medial Sagittal plane Posterior 3rd of C1/2 joint (50 o cephalad) ) 1/3 2/3 Vertebral groove L=34-48mm
- 23. C1/2 transarticular screw (Magerl 1987) Entry point L/M mid point 3mm from lower end Axial plane 10 o medial Drilling 3mm Mid L=34-48mm
- 24. C1/2 transarticular screw (Magerl 1987) Sagittal plane Posterior 3rd of C1/2 joint (50 o cephalad) ) Iliac bone graft Screwing L=34-48mm
- 25. C1/2 transarticular screw (Magerl 1987) Sagittal plane Posterior 3rd of C1/2 joint (50 o cephalad) ) L=34-48mm 3mm Mid
- 26. Ramses British museum Rosetta stone Surgical technique of C3-7 LMS
- 27. 10 o 25 o 45 o 0 o 2mm medial to center Magerl Roy-Camille Mid & upper 1/3 Various methods of LMS (C3-7) Parallel to facet L=20-24mm
- 28. C3-7 LMS (Magerl 1991) 2mm medial 25 o 45 o L=22-26mm
- 29. C3-7 LMS (Roy-Camille 1972) Upper 1/3 10 o 0 o L=18-22mm
- 30. London eye Surgical technique of C3-7 Transarticular screw
- 31. C3-7 Transarticular(facet) screw L=14-18mm (DalCanto 2005) (Takayasu 2003) Safe, but more facets fracture High risk of VA & nerve root injury Perpendicular to joint 20 o lateral Straight Perpendicular to joint
- 32. C3-7 Transarticular(facet) screw Tricortical screw is sometimes enough
- 33. Westminster Abbey Surgical technique of C7 laminar screw
- 34. Surgical technique of C7 laminar screw
- 35. Surgical technique of C7 laminar screw
- 36. Thank you for your attention ขอบคุณ มาก ครัค่ะ Danke schön Děkuji Terima kasih
Editor's Notes
- Good morning, colleagues. Today I would like to talk about Surgical techniques of various methods of posterior cervical screw placement.
- Nowadays, we can use a lot of types of cervical screws. For C1, you can put lateral mass screws. If you plan to perform atlantoaxial arthrodesis, Transarticular screw technique is very popular. For C2, we can apply many types of screws, including laminar screws, pars screws, and pedicle screws. Subaxial lesions will be treated by pedicle screws, lateral mass screws, and transarticular facet screws.
- Let’s get started with C1 lateral mass screw technique.
- As prof Suchomel mentioned before, C1-2 anatomy is quit different from that of subaxial spine. Suboccipital venous plexus is easy to bleeds, so we should pay attention to this vein for C1-2 exposure. We should not injure 1 st and 2 nd cervical nerve roots, which may become the cause of occipitalgia. There are 4 important muscles, including rectus capitis posterior minor and major muscle,, superior and inferior oblique muscle.
- As you know, the shape of Atlas is very unique. The thickness of C1 lamina is average 4.6 mm, which is important for Tan’s technique. The height of lateral mass is average 13 mm, and its width is average 18 mm. If you plan to Goel method, AP length of lateral mass is about 20mm, and the length from lamina to anterior wall using Tan method, is about 30mm. You should remind that VA is located cranial margin 15mm from midline.
- There are three methods of C1 LMS placement. On your left, Figures show the Direct insertion technique invented by Dr Goel. The entry point of this technique is Lateral/Medial mid point and 2 mm above the articular surface. The axial angle is 15 degrees medially and sagittal angle is 15 degrees cephalad. In the middle of the slide, this is a translaminar technique introduced by Dr Tan. The entry point of this technique is through the lamina, so the lamina breakage is a problem. The axial angle is straight and the sagittal angle is 5 degrees cephalad. In 2006, Dr Lee reported Notching method, which seems to be ideal method. This technique is making a notch just below the Tan’s method and screw angulations are between previous two methods.
- Dr Goel in India reported this method. The entry point of this technique is Lateral/Medial mid point of lateral mass and 2 mm above the articular surface. Originally, he recommend to cut C2 nerve roots. However, to prevent severe occipitalgia, you should preserve C2 nerve roots. Choose the half thread screw to avid the nerve irritation. Bicortical penetration is mandatory to enhance the pullout strength. Screw angulation are 15 degrees medially and 15 degrees cephalad.
- This method was reported by Dr Tan in China. The entry point of this technique is 19 mm lateral of midline and 2 mm superior of lower margin. If you apply this technique, it is very easy to control the venous bleeding. Because you don’t have to expose the C1/2 venous plexus. Choose the full thread screw to enhance the pullout strength. Bicortical penetration is not necessary, so there is no risk of carotid artery injury. The axial angle is straight and the sagittal angle is 5 degrees cephalad.
- Next technique is C2 laminar screws.
- C2 laminar screw technique was first reported by Dr Wright in the USA. This method is very safe because there is no risk of VA injury. The entry point is the junction of C-2 spinous process and lamina on the right, close to the rostral margin of the C-2 lamina. The length of screw is about 30mm, and the angle should be 50 to 60 degrees lateral.
- The entry point of the left lamina is the junction of C-2 spinous process and lamina on the right, close to the rostral margin of the C-2 lamina. Make a hole and plobing. You should check not to penetrate medial cortex, which causes spinal cord injury. The screw length should be approximately 30 mm, A second screw was placed into the right lamina, with the entry point at the junction of the spinous process and the left. The angle should be 50 to 60 degrees. This is the clear bone model for better understanding.
- Next screw is C2 pedicle screw.
- This screw was first reported by Dr Judet in France. The Entry point of this screw is about the center of the lateral mass. The axial angle is 40 degrees medially and sagittal angle should be 30 degrees cephalad.
- Until recently, pedicle screws for C3-6 are regarded as very dangerous screws. In 1997, Prof Abumi in Japan applied C3-6 pedicle screws safely. The entry point are slightly lateral to the center of the articular mass, close to the inferior margin of the inferior articular process. The landmark is the noch. The angle are 25 o to 45 o medially. However, they must be confirmed on CAT scan.
- The entry point of this screw is mid point of upper and lower facets. To avoid VA injury, you should aim 40 degrees medially and 30 degrees cephalad. You should know the VA is located laterally and inferiorly. The screw length is about 26mm. This is a clear bone model. The percentage of VA injury is relatively high.
- This slide shows Goel’s method. This constructs are made of C1 LMSs and C2 pedicle screws.
- This slide shows the famous elephant riding.
- Let’s move to the C2 pars screw technique.
- Historically speaking, this C2 pars interarticularis screw has been regarded as a pedicle screw. However, this screw is not the true pedicle screw because the screw stays in the pars interarticularis. The axial angle is 10 degrees medially and sagittal angle is 50 degrees cephalad.
- The entry point is mid point of lateral mass. The axial angle is 10 degrees medially and 40 degrees cephalad. If you penetrate the C1/2 joint, this screw become transarticular screw.
- Next is a C1/2 transarticular screw technique.
- C1/2 transarticular screw technique was first reported by Dr Magerl in Switzerland. The entry point of this screw is almost same as that of pars screw, but a little bit different. The entry point is Medial and lateral mid point and 3mm above the lower end of inferior articular process. The axial angle is 10 medial and the sagittal angle is 50 cephalad aiming posterior one third of C1/2 lateral joint.
- This is the entry point and aiming 10 degrees medially in axial plane.
- To avoid VA injury, you should aim the posterior third of C1/2 lateral joint.
- The entry point is the medial and lateral mid point and 3mm above the lower end of inferior articular process. You should confirm the C1/2 lateral joint directly and aim the center of the joint. The axial angle should be 10 medially and the sagittal angle is 50 cephalad. The screw length is about 40mm. In the clear bone model, the screw is penetrating the C1/2 lateral joint. To avoid the VA injury, you should aim posterior one third of C1/2 lateral joint. Again you should remember that this screw is the strongest but the most dangerous.
- Next is subaxial LMS.
- Among a lot of techniques, these two methods are very popular. The entry point of Magerl technique is 2mm medial to center. But that of Roy-Camille technique is located in the meddle and upper third of lateral mass. The axial angles are 25 degrees medially and 10 degrees medially, respectively. The sagittal angles are 45 degrees medially, which means parallel to facet. and perpendicular to lateral mass by Roy-Camille technique.
- Let me show you the Magerl technique using left C4 lateral mass. The entry point is 2mm medial to center of lateral mass. The axial angle is 25 degrees laterally. The sagittal angle is 45 degrees medially, which means parallel to facet joint. Screws should be penetrated bilateral cortex to enhance the screw pull-out strength. However, long screws are dangerous, so you should pay attention to VA and nerve root injury.
- This is the Roy-Camille technique using left C5 lateral mass. The entry point is middle and upper third of lateral mass. The axial angle is 10 degrees laterally. The sagittal angle is perpendicular to lateral mass. This is the clear bone model. The screw length is average 20mm.
- Next screw is subaxial transarticular screw or facet screw.
- Chairman and professor Takayasu first reported cervical transarticular screw in 2003. The entry point of this screw is center of lateral mass. The axial angle is straight according to Professor Takayasu’s method. And the sagittal angle is perpendicular to the joint. DalCanto in USA modified this technique and aim 20 degrees lateral in axial plane to avoid VA injury. This method is safer, but more facets fracture.
- Originally, this screw needs four cortical penetration. However, I feel tricortical screwing is enough to maintain the stability, if you use this screw in the long construct.
- The final screw is C7 laminar screw.
- We reported every laminar diameter for laminar screw insertion. According to our results, the diameter of C7 is the second biggest next to C2 lamina. It is impossible to insert the laminar screw from C4 to C6 lamina.
- The entry point is almost same as C2 laminar screw. The entry point of the left lamina is the junction of C-7 spinous process and lamina on the right, close to the rostral margin of the C-7 lamina. A second screw was placed into the right lamina, with the entry point at the junction of the spinous process and the left. The angle should be 50-60 degrees. This is the clear bone model for better understanding.
- Thank you for your attention. コップ（ pu ）クン マーク クラッ（プ） Khob khun Mark Krab