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48
Fig. 4.7 Head fixed to Mayfield holder with inserted Crockard’s
mouth distractor. Notice the attached DRA for navigational
system
wrapping, we insert Crockard’s transoral distraction frame (Codman™). The insertion and stability
of the frame is crucial for uneventful surgery and it
is frequently secured by a submandibular support of
its lower part. The tongue must not be interposed
between the teeth and the lower blade of the distractor. The endotracheal tube is located laterally (on the
right side in our setup) under the large caudal lingual
distractor blade. The uvula is stitched to a rubber tubing inserted through nostril to epipharynx, and then
everted cranially (Fig. 4.8). Additional isolated spatulas for reverting the soft palate are also available in
the set. It is possible to split the soft palate in order
Fig. 4.8 Soft palate reverted to nasopharynx by traction of
transnasally introduced cannula stitched to uvula
4 Surgical Approaches
Fig. 4.9 Final setup for microsurgical transoral odontoidectomy
to get a better view cranially, no more than 1 cm can
be achieved by this maneuver, however. If performed
anyway, the uvula has to be left on one side. We always
try to avoid any incision in soft palate as there is a high
risk of postoperative velopalatal insufficiency causing
rhinolalia and nasal alimentary regurgitation. We have
never drilled away any part of the hard palate in our
series of TO-treated patients. When necessary, opendoor maxillotomy offers a more convenient option.
After final positioning of Crockard’s frame, we disinfect the surgical field again and perform the final wrapping (Fig. 4.9). The anterior tubercle of the atlas is
palpated to localize the midline. Uvula may be used as
an optional orientation point in case of rotatory dislocation of atlas. A vertically oriented longitudinal knife
scratch is performed on the surface of retropharyngeal
mucosa at the level of anterior atlantal tubercle and
local anesthetic with adrenalin is applied. The injection distorts natural anatomy and marking with a knife
scratch keeps surgeon’s eye on the midline. Infiltrated
mucosa is incised above the tubercle and all the way
to the bone. This incision avoids any anatomical structures of importance. The anterior tubercle of C1 must
be dissected free as the crucial landmark. It is of utmost
importance to be sure that the atlas is not rotated as this
may substantially change the position of the tubercle!
The muscle attachments but namely the firm attachment of anterior longitudinal ligament should be cut
sharply off the tubercle with the sharp long-shaft knife.
The anterior arch of the atlas is exposed bilaterally by
subperiostal dissection (around 1 cm to both sides;
VA is normally located more than 2 cm from the midline). We continue to dissect sharply caudally to the
body of C2. In the exposure designed for the purpose
4.5 Transoral Approach
49
of odontoidectomy, the disk C2/3 represents the most
caudal landmark. Its position may be verified with a
dissector and palpation or fluoroscopy. If necessary, it
is usually possible to expose approximately the upper
half of C3 body caudally. Lateral extent of the exposure at the level of C2 is limited by the position of VA
(10–15 mm from the midline at this level). Cranial dissection, in particular, should be performed carefully as
only the anterior atlanto-occipital membrane protects
the dura laterally between atlas and clivus. The clival
edge has to be identified before exposed subperiostally.
Caudal and cranial ridge of the atlas arch can then be
dissected with a thin periostal elevator. The anterior
C1 arch can then be removed easily either macroscopically with a rongeur (Fig. 4.10) or drilled out under
microscope. The interlaminar distance of 12–15 mm
allows full anterior exposure of the odontoid. If necessary, the approach can be safely extended laterally
to the lateral masses of C1. Further steps depend on
whether dens deformity caused by underlying pathology is present or not. If well demarcated, the apical
ligaments (e.g., apical and allar) are sharply cut and
resected before the odontoid is cut at its base so that
PLL may be reached (Fig. 4.11a, b, c). The odontoid peg
is then mobilized from its tip while elevated with a flat
bone hook (Caspar’s osteophyte hook) until it breaks
(Fig. 4.11d). The free fragment can thus be removed
en bloc. The odontoid is sometimes poorly delimited
or dislocated too deep or even behind clivus. In such
Fig. 4.10 Anterior arch of atlas grasped by rongeur before its
removal
situations, we use an egg-shell milling with high-speed
drilling through the tissue until the opposite cortical
bone is reached. We often start the removal at the tip
and continue caudally to avoid free movement of the
apical fragment during drilling. The transversal atlantal ligament can be seen behind the peg finally. It is
loosened in cases of RA or developmental deformities
and can be then removed. However, it should be left
in place if it is strong and does not cause compression of the spinal cord. Leaving the strong ligament in
place helps to resist eventual distracting forces on atlas
and its vertical movement. Removal of the odontoid
is often satisfactory for adequate decompression. It is
not necessary to remove the soft tissue in patients with
RA or odontoid pseudoarthrosis if we plan a posterior
stabilization later during the same surgery.
Previous recommendation is not applicable in
patients with developmental anomalies, infectious
bone damage, and/or tumors. Depending on the type of
procedure and pathology, the standard transoral
approach should be appropriately modified: the atlas
arch partially spared, the clivus edge cut out, the whole
anterior axis removed (with or without cage or prosthesis replacing C2 body) etc.
The approach can be extended cranially (maxillotomy) and/or caudally (mandibulotomy), but such an
extension should better be a planned step rather than a
result of decision made intraoperatively. The subarachnoid space has to be opened very exceptionally, mainly
in case of tumors (clival chordoma). Whenever possible, we prefer the far lateral approach to remove midline intradural pathologies of CVJ.
Watertight suture with use of dural substitutes is
necessary. It might be technically difficult and adhesives and self-adhering patches are often applied. Use
of external lumbar drainage is mandatory in cases of
intradural procedure. However, the pressure of cerebrospinal fluid should be maintained positive, so that
the content of oral cavity including potentially pathogenic microbial flora is not prompted to migrate intradurally as a result of negative pressure gradient. Under
normal circumstances, we leave external CSF drainage
for 7–10 days postoperatively. The decompressive procedure is finished by closing the pharyngeal wall in
one or two layers. Nasogastric feeding tube is inserted
at the end of surgery and left in place for 5–7 days.
Most of our transoral surgeries involved a primarily
unstable situations or such a situation was created by
the decompression performed. Stabilization is therefore often necessary and we tend to perform it in a
50
4 Surgical Approaches
Fig. 4.11 Transoral odontoidectomy. (a) Demarking of the odontoid process. (b) High speed drill undercutting of the base.
(c) Drilling of the odontoid base controlled by fluoroscopy. (d) Outward braking of the peg
single session, e.g., immediately after the closure of
the transoral wound.
It is of advantage to attach the Mayfield’s head
clamp in a way that allows head fixation in both prone
and supine positions without any need for replacement
of the skull pins (Fig. 4.1). The motor-evoked responses
must be carefully monitored and should not alter dur-
without splitting of the tongue can be justified if the
mouth cannot be opened enough. Most of tumors of the
UCS are of metastatic origin and radical extirpation is
seldom possible. For palliative tumor resection and stabilization, the high anterolateral approach is sufficient
in the majority of cases. We always invite the maxillofacial surgeon to perform the extension of the approach.
ing repositioning of the patient.
There are only few distinct situations where the
extension of the classical TO approach makes sense, as
example when the border of pathological process cannot be reached and/or the mouth cannot be opened wide
4.5.3 Minimally Invasive Approaches to Retropharyngeal UCS
enough to insert instruments. A need for cranial extension is more frequent. Maxillotomy may be used in
adult patients with tumors (chordoma, sarcoma, chondroma, osteoblastoma, etc.) and/or with congenital/
acquired deformities causing flattening of the skull base
(Fig. 7.1, Chap. 7, Fig. 20.13, Chap. 20). Mandibulotomy
Endoscopic techniques were brought to the area of
UCS by neurosurgeons familiar with endoscopic
and image-guided surgery of the brain. Veres et al.
used navigation-based technique for transoral surgeries in three patients. By using a halo vest during
References
51
a preoperative scanning, he elegantly overcame the
problem of the shift due to mobility. The resulting
accuracy was reported to be 1.5–3 mm [72].
Other authors have confirmed positive experience
with image guidance for TO surgery [70, 74]. The main
problem of image-guided techniques in spine surgery –
the accurate registration of mobile vertebras as landmarks – has been solved by the use of fluoroscopy for in
situ registration. These technologies represent a futuristic reality that is available already today, and they are
helpful particularly in complex surgical cases.
Endoscopy-assisted surgery was originally introduced to increase the visibility as well as illumination of
the surgical field, but also to avoid soft palate split during standard TO approaches [21]. Increasing popularity
of endoscopy and experience from using it in pituitary
surgery allowed neurosurgeons to extend its use to the
surgery of the clivus and the region of CVJ. Based on
cadaveric study of Alfieri et al. [2], Kasam et al. resected
the odontoid process in a 73-year-old woman, using a
transnasally introduced endoscope [42]. They used binostril approach. The caudally based mucosal flap was
located above the level of soft palate. Introduction of
adapted long instruments was image guided and controlled with fluoroscopy. Their patient (suffering from
RA) did well after the surgery and the extent of odontoidectomy was nicely documented by CT. The authors
called the approach as “expanded endonasal” (EEA).
Similarly, Hansen et al. performed a transnasal decompression in a patient with basilar invagination [29]. Wu
et al. [79] performed endoscopic removal of odontoid in
three patients (RA in two, trauma in one) using only one
nostril and self-retaining holders. Transclival trajectory
allows sparing of C1 arch, thus reducing the risk of
extensive destabilization.
To avoid infectious complications of transoral or
transnasal surgery (transcavital approach), Wolinsky
et al. [77] developed endoscopic transcervical imageguided odontoidectomy (ETO). The procedure was
successfully performed in three patients with basilar
impression, with only one complication (CSF leakage). The endoscope was introduced through adapted
tubular retractor (METRx™, Medtronic) to the base of
C2 in a similar fashion as screws for odontoid fixation.
The anatomical landmarks were registered using C-arm
fluoroscopy and following surgical steps were performed under image guidance. The authors were able
to decompress CVJ by gradual drilling under endoscopic control. ETO technique was later used at the
same institution for successful treatment of four pediatric patients suffering from basilar invagination and
cranial settling [46]. Although ETO and EEA are really
minimally invasive techniques, they cannot be regarded
as pure endoscopy because the endoscope is introduced
via a tubular system or nostrils, parallel with drill and
suction. Recently, Baird et al. [7] compared all three
endoscopic techniques in a cadaver study. Evaluating
findings from nine cadavers, the authors found the
average distance to the surgical target to be similar for
all three methods – 94 mm by endonasal, 102 mm by
transoral, and 100 mm by transcervical route. However,
the approach angles necessary to reach the target structures differed significantly. The authors concluded that
endoscopic transoral approach allows exposure of the
largest surgical field. The transcervical route, certainly
suitable for resection of the odontoid, does not allow
safe resection of the lower clivus.
4.5.3.1 Our Preference
The philosophy of minimally invasive approaches performed either from small incisions with the help of
image guidance or endoscopically assisted clearly
stand opposite to the techniques aiming at maximal
exposure, represented by transpalatopharyngeal route
with medial mandibuloglossotomy. Although we do
not have personal experience with endoscopy in surgery of UCS and CVJ at our institution, we feel that
there is a place for it in selected indications. Further
development of minimally invasive techniques based
on virtual image guidance can definitely be expected.
References
1. Ai, F., Yin, Q., Wang, Z., et al.: Applied anatomy of transoral
atlantoaxial reduction plate internal fixation. Spine (Phila Pa
1976) 31, 128–132 (2006)
2. Alfieri, A., Jho, H.D., Tschabitscher, M.: Endoscopic endonasal approach to the ventral cranio-cervical junction: anatomical study. Acta Neurochir (Wien) 144, 219–225 (2002).
discussion 225
3. al-Mefty, O., Borba, L.A., Aoki, N., et al.: The transcondylar
approach to extradural nonneoplastic lesions of the craniovertebral junction. J Neurosurg 84, 1–6 (1996)
4. Alonso, W.A., Black, P., Connor, G.H., et al.: Transoral
transpalatal approach for resection of clival chordoma.
Laryngoscope 81, 1626–1631 (1971)
52
4 Surgical Approaches
5. Arbit, E., Patterson Jr., R.H.: Combined transoral and median
labiomandibular glossotomy approach to the upper cervical
spine. Neurosurgery 8, 672–674 (1981)
6. Archer, D.J., Young, S., Uttley, D.: Basilar aneurysms: a new
transclival approach via maxillotomy. J Neurosurg 67, 54–58
(1987)
7. Baird, C.J., Conway, J.E., Sciubba, D.M., et al.: Radiographic
and anatomic basis of endoscopic anterior craniocervical
decompression: a comparison of endonasal, transoral, and
transcervical approaches. Neurosurgery 65, 158–163 (2009).
discussion 163–154
8. Barbour, J.R.: Screw fixation in fracture of the odontoid process. S Aust Clin 5, 20–24 (1971)
9. Bertalanffy, H., Seeger, W.: The dorsolateral, suboccipital,
transcondylar approach to the lower clivus and anterior portion of the craniocervical junction. Neurosurgery 29, 815–
821 (1991)
10. Bhangoo, R.S., Crockard, H.A.: Transmaxillary anterior
decompressions in patients with severe basilar impression.
Clin Orthop Relat Res 359, 115–125 (1999)
11. Brookes, J.T., Smith, R.J., Menezes, A.H., et al.: Median
labiomandibular glossotomy approach to the craniocervical
region. Childs Nerv Syst 24, 1195–1201 (2008)
12. Cocke Jr., E.W., Robertson, J.H., Robertson, J.T., et al.: The
extended maxillotomy and subtotal maxillectomy for excision of skull base tumors. Arch Otolaryngol Head Neck Surg
116, 92–104 (1990)
13. Crockard, H.A.: Transoral approach to intra/extradural
tumors. In: Sekhar, L.N., Janecka, I.P. (eds.) Surgery of cranial base tumors, pp. 225–234. Raven, New York (1993)
14. Crockard, H.A.: Transoral surgery: some lessons learned. Br
J Neurosurg 9, 283–293 (1995)
15. Crockard, H.A., Johnston, F.: Development of transoral
approaches to lesions of the skull base and craniocervical
junction. Neurosurg Q 3, 61–82 (1993)
16. de Andrade, J.R., Macnab, I.: Anterior occipito-cervical
fusion using an extra-pharyngeal exposure. J Bone Joint
Surg Am 51, 1621–1626 (1969)
17. Delgado, T.E., Garrido, E., Harwick, R.D.: Labiomandibular,
transoral approach to chordomas in the clivus and upper cervical spine. Neurosurgery 8, 675–679 (1981)
18. Dickman, C.A., Crawford, N.R., Brantley, A.G., et al.:
Biomechanical effects of transoral odontoidectomy.
Neurosurgery 36, 1146–1152 (1995). discussion 1152–1143
19. Dickman, C.A., Locantro, J., Fessler, R.G.: The influence of
transoral odontoid resection on stability of the craniovertebral junction. J Neurosurg 77, 525–530 (1992)
20. Du Toit, G.: Lateral atlanto-axial arthrodesis. A screw fixation technique. S Afr J Surg 14, 9–12 (1976)
21. Frempong-Boadu, A.K., Faunce, W.A., Fessler, R.G.:
Endoscopically assisted transoral-transpharyngeal approach
to the craniovertebral junction. Neurosurgery 51, S60–S66
(2002)
22. George, B., Laurian, C.: Surgical approach to the whole
length of the vertebral artery with special reference to the
third portion. Acta Neurochir (Wien) 51, 259–272 (1980)
23. Gilsbach, J.M., Eggert, H.R., Seeger, W.: The dorsolateral
approach in ventrolateral craniospinal lesions. In: Voth, D.,
Glees, P. (eds.) Diseases in the cranio-cervical junction.
Anatomical and pathological aspects and detailed clinical
accounts, pp. 359–364. Gruyter, Berlin, New York (1987)
24. Grime, P.D., Haskell, R., Robertson, I., et al.: Transfacial
access for neurosurgical procedures: an extended role for the
maxillofacial surgeon. I. The upper cervical spine and clivus. Int J Oral Maxillofac Surg 20, 285–290 (1991)
25. Grime, P.D., Haskell, R., Robertson, I., et al.: Transfacial
access for neurosurgical procedures: an extended role for the
maxillofacial surgeon. II. Middle cranial fossa, infratemporal fossa and pterygoid space. Int J Oral Maxillofac Surg 20,
291–295 (1991)
26. Grob, D.: Atlantoaxial immobilization in rheumatoid arthritis: a prophylactic procedure? Eur Spine J 9, 404–409 (2000)
27. Grob, D., Wursch, R., Grauer, W., et al.: Atlantoaxial fusion
and retrodental pannus in rheumatoid arthritis. Spine (Phila
Pa 1976) 22, 1580–1583 (1997). discussion 1584
28. Hadley, M.N., Spetzler, R.F., Sonntag, V.K.: The transoral
approach to the superior cervical spine. A review of 53 cases
of extradural cervicomedullary compression. J Neurosurg
71, 16–23 (1989)
29. Hansen, M.A., da Cruz, M.J., Owler, B.K.: Endoscopic
transnasal decompression for management of basilar invagination in osteogenesis imperfecta. J Neurosurg Spine 9,
354–357 (2008)
30. Harms, J., Schmelze, R., Stolze, D.: Osteosynthesen im
occipito-cervikalen Übergang vom transoralen Zugang aus,
XVII SICOT World Congress Abstracts. Demeter Verlag,
Munich (1987)
31. Henry, A.K.: Extensile exposure, pp. 58–74. E & S
Livingstone, Edinburgh and London (1957)
32. Heros, R.C.: Lateral suboccipital approach for vertebral and
vertebrobasilar artery lesions. J Neurosurg 64, 559–562
(1986)
33. Hitchcock, E., Cowie, R.: Transoral-transclival clipping of a
midline vertebral artery aneurysm. J Neurol Neurosurg
Psychiatry 46, 446–448 (1983)
34. James, D., Crockard, H.A.: Surgical access to the base of
skull and upper cervical spine by extended maxillotomy.
Neurosurgery 29, 411–416 (1991)
35. Jiang, L.S., Shen, L., Wang, W., et al.: Posterior atlantoaxial
dislocation without fracture and neurologic deficit: a case
report and the review of literature. Eur Spine J 28, 28 (2009)
36. Jones, R.E., Bucholz, R.W., Schaefer, S.D., et al.: Cervical
osteomyelitis complicating transpharyngeal gunshot wounds
to the neck. J Trauma 19, 630–634 (1979)
37. Jones, D.C., Hayter, J.P.: The superiorly based pharyngeal
flap: a modification of the transoral approach to the upper cervical spine. Br J Oral Maxillofac Surg 35, 368–369 (1997)
38. Jones, D.C., Hayter, J.P., Vaughan, E.D., et al.: Oropharyngeal
morbidity following transoral approaches to the upper cervical spine. Int J Oral Maxillofac Surg 27, 295–298 (1998)
39. Kanavel, A.B.: Bullet locked between atlas and the base of
the skull: Technique for removal through the mouth. Surg
Clin 1, 361–366 (1919)
40. Kandziora, F., Kerschbaumer, F., Starker, M., et al.:
Biomechanical assessment of transoral plate fixation for
atlantoaxial instability. Spine (Phila Pa 1976) 25, 1555–1561
(2000)
41. Kandziora, F., Mittlmeier, T., Kerschbaumer, F.: Stagerelated surgery for cervical spine instability in rheumatoid
arthritis. Eur Spine J 8, 371–381 (1999)
42. Kassam, A.B., Snyderman, C., Gardner, P., et al.: The
expanded endonasal approach: a fully endoscopic transnasal
References
53
approach and resection of the odontoid process: technical
case report. Neurosurgery 57, E213 (2005). discussion E213
43. Kingdom, T.T., Nockels, R.P., Kaplan, M.J.: Transoraltranspharyngeal approach to the craniocervical junction.
Otolaryngol Head Neck Surg 113, 393–400 (1995)
44. Lee, S.T., Fairholm, D.J.: Transoral anterior decompression
for treatment of unreducible atlantoaxial dislocations. Surg
Neurol 23, 244–248 (1985)
45. McAfee, P.C., Bohlman, H.H., Riley Jr., L.H., et al.: The
anterior retropharyngeal approach to the upper part of the
cervical spine. J Bone Joint Surg Am 69, 1371–1383 (1987)
46. McGirt, M.J., Attenello, F.J., Sciubba, D.M., et al.:
Endoscopic transcervical odontoidectomy for pediatric basilar invagination and cranial settling. Report of 4 cases. J
Neurosurg Pediatr 1, 337–342 (2008)
47. Menezes, A.H.: Anterior approaches to the craniocervical
junction. Clin Neurosurg 37, 756–769 (1989)
48. Menezes, A.H., VanGilder, J.C.: Transoral-transpharyngeal
approach to the anterior craniocervical junction. Ten-year
experience with 72 patients. J Neurosurg 69, 895–903 (1988)
49. Milbrink, J., Nyman, R.: Posterior stabilization of the cervical spine in rheumatoid arthritis: clinical results and magnetic resonance imaging correlation. J Spinal Disord 3,
308–315 (1990)
50. Mouchaty, H., Perrini, P., Conti, R., et al.: Craniovertebral
junction lesions: our experience with the transoral surgical
approach. Eur Spine J 18(Suppl 1), 13–19 (2009)
51. Mullan, S., Naunton, R., Hekmat-Panah, J., et al.: The use of
an anterior approach to ventrally placed tumors in the foramen magnum and vertebral column. J Neurosurg 24, 536–
543 (1966)
52. Naderi, S., Crawford, N.R., Melton, M.S., et al.:
Biomechanical analysis of cranial settling after transoral
odontoidectomy. Neurosurg Focus 6, e7 (1999)
53. Naderi, S., Pamir, M.N.: Further cranial settling of the upper
cervical spine following odontoidectomy. Report of two
cases. J Neurosurg 95, 246–249 (2001)
54. Oya, S., Tsutsumi, K., Shigeno, T., et al.: Posterolateral
odontoidectomy for irreducible atlantoaxial dislocation: a
technical case report. Spine J 4, 591–594 (2004)
55. Park, S.H., Sung, J.K., Lee, S.H., et al.: High anterior cervical approach to the upper cervical spine. Surg Neurol 68,
519–524 (2007). discussion 524
56. Pasztor, E., Vajda, J., Piffko, P., et al.: Transoral surgery for
craniocervical space-occupying processes. J Neurosurg 60,
276–281 (1984)
57. Rhines, L.D., Fourney, D.R., Siadati, A., et al.: En bloc
resection of multilevel cervical chordoma with C-2 involvement. Case report and description of operative technique. J
Neurosurg Spine 2, 199–205 (2005)
58. Roy-Camille, R., de la Caffiniére, J.H., Saillant, G.: Les
traumatismes du rachis cervical superieur C1-C2. Masson et
Cie, Paris (1973)
59. Ruf, M., Melcher, R., Harms, J.: Transoral reduction and
osteosynthesis C1 as a function-preserving option in the
treatment of unstable Jefferson fractures. Spine (Phila Pa
1976) 29, 823–827 (2004)
60. Scoville, W.B., Sherman, I.J.: Platybasia, report of 10 cases
with comments on familial tendency, a special diagnostic
sign, and the end results of operation. Ann Surg 133, 496–
502 (1951)
61. Sen, C.N., Sekhar, L.N.: An extreme lateral approach to
intradural lesions of the cervical spine and foramen magnum. Neurosurgery 27, 197–204 (1990)
62. Simmons, E.H., Du Toit Jr., G.: Lateral atlantoaxial arthrodesis. Orthop Clin North Am 9, 1101–1114 (1978)
63. Skaf, G.S., Sabbagh, A.S., Hadi, U.: The advantages of submandibular gland resection in anterior retropharyngeal
approach to the upper cervical spine. Eur Spine J 16, 469–
477 (2007)
64. Southwick, W.O., Robinson, R.A.: Surgical approaches to
the vertebral bodies in the cervical and lumbar regions. J
Bone Joint Surg Am 39-A, 631–644 (1957)
65. Spetzler, R.F., Selman, W.R., Nash Jr., C.L., et al.: Transoral
microsurgical odontoid resection and spinal cord monitoring. Spine (Phila Pa 1976 4, 506–510 (1979)
66. Steinmetz, M.P., Mroz, T.E., Benzel, E.C.: Craniovertebral
junction: biomechanical considerations. Neurosurgery 66,
A7–A12 (2010)
67. Suchomel, P., Buchvald, P., Barsa, P., et al.: Single-stage
total C-2 intralesional spondylectomy for chordoma with
three-column reconstruction. Technical note. J Neurosurg
Spine 6, 611–618 (2007)
68. Sukoff, M.H., Kadin, M.M., Moran, T.: Transoral decompression for myelopathy caused by rheumatoid arthritis of
the cervical spine. Case report. J Neurosurg 37, 493–497
(1972)
69. Ture, U., Pamir, M.N.: Extreme lateral-transatlas approach
for resection of the dens of the axis. J Neurosurg 96, 73–82
(2002)
70. Ugur, H.C., Kahilogullari, G., Attar, A., et al.: Neuronavigationassisted transoral-transpharyngeal approach for basilar invagination – two case reports. Neurol Med Chir (Tokyo) 46,
306–308 (2006)
71. Vaccaro, A.R., Lehman, A.P., Ahlgren, B.D., et al.: Anterior
C1-C2 screw fixation and bony fusion through an anterior retropharyngeal approach. Orthopedics 22, 1165–1170 (1999)
72. Veres, R., Bago, A., Fedorcsak, I.: Early experiences with
image-guided transoral surgery for the pathologies of the
upper cervical spine. Spine (Phila Pa 1976 26, 1385–1388
(2001)
73. Vishteh, A.G., Crawford, N.R., Melton, M.S., et al.: Stability
of the craniovertebral junction after unilateral occipital condyle resection: a biomechanical study. J Neurosurg 90,
91–98 (1999)
74. Vougioukas, V.I., Hubbe, U., Schipper, J., et al.: Navigated
transoral approach to the cranial base and the craniocervical
junction: technical note. Neurosurgery 52, 247–250 (2003).
discussion 251
75. Whitesides, TEj: Lateral retropharyngeal approach to the
upper cervical spine. In: Sherk, H.H., Dunn, E.J., Eismont,
F.J., et al. (eds.) The cervical spine, pp. 796–804. Lippincott,
Philadelphia (1989)
76. Whitesides, T.E., Kelly, R.P.: Lateral approach to the upper
cervical spine for anterior fusion. South Med J 59, 879–883
(1966)
77. Wolinsky, J.P., Sciubba, D.M., Suk, I., et al.: Endoscopic
image-guided odontoidectomy for decompression of basilar
invagination via a standard anterior cervical approach.
Technical note. J Neurosurg Spine 6, 184–191 (2007)
78. Wood, D.E., Good, T.L., Hahn, J., et al.: Decompression of
the brain stem and superior cervical spine for congenital/
54
4 Surgical Approaches
acquired craniovertebral invagination: an interdisciplinary
approach. Laryngoscope 100, 926–931 (1990)
79. Wu, J.C., Huang, W.C., Cheng, H., et al.: Endoscopic transnasal transclival odontoidectomy: a new approach to decompression: technical case report. Neurosurgery 63,
ONSE92–ONSE94 (2008). discussion ONSE94
80. Young, W.F., Boyko, O.: Magnetic resonance imaging confirmation of resolution of periodontoid pannus formation
following C1/C2 posterior transarticular screw fixation. J
Clin Neurosci 9, 434–436 (2002)
81. Youssef, A.S., Guiot, B., Black, K., et al.: Modifications of
the transoral approach to the craniovertebral junction: anatomic study and clinical correlations. Neurosurgery 62,
145–154 (2008). discussion 145–154
82. Zygmunt, S., Saveland, H., Brattstrom, H., et al.: Reduction
of rheumatoid periodontoid pannus following posterior
occipito-cervical fusion visualised by magnetic resonance
imaging. Br J Neurosurg 2, 315–320 (1988)
Basic Principles of Reconstruction Techniques
O. Choutka and P. Suchomel
5
The craniovertebral junction (CVJ) is a mechanical
part of the spine that offers the most significant amount
of mobility when compared to other segments, particularly in flexion, extension, and rotation. Under physiological circumstances, stability and mobility of the
CVJ is facilitated by unique morphology of the upper
cervical vertebrae that form the levers in motion that
are restrained by ligaments and facilitated by surrounding local and distant muscles. The atlanto-occipital
and atlantoaxial joints act as pivots of the complex
motion. Pathological processes, such as arthritides and
tumors, as well as surgical decompressive procedures
can result in profound violation of the balanced construct and thus cause instability, loss of function, pain,
and neurological compromise. Prior to embarking on
any potentially destabilizing procedure at CVJ, a surgeon should have a plan for reconstruction that will
stabilize appropriately. The unique nature of the upper
cervical spine (UCS) vertebrae offers an opportunity
for not only stabilizing rigid constructs but also for a
number of direct osteosynthetic designs that preserve
motion of the segment. In general, constructs of the
CVJ involve those designed for ventral approaches and
posterior instrumentation, or both. Basic biomechanical principles and forces generated by any implant
must be respected and understood when instrumenting
the UCS and are covered elsewhere in the book. The
biomechanical properties of the CVJ must be either
O. Choutka
Department of Neurosurgery,
University of Cincinnati College of Medicine,
231 Albert Sabin Way,
Cincinnati, OH 45267-0515, USA
P. Suchomel
Department of Neurosurgery,
Neurocenter, Regional Hospital Liberec,
Husova St.10, 46063 Liberec, Czech Republic
matched or appropriately counteracted by any construct that is to stabilize and maintain motion and
appropriate alignment. Several basic reconstruction
techniques are discussed in this section but the reader
should refer to Chap. 2 for biomechanical principles
and Chap. 6 for specific reconstructions.
5.1 Defect/Instability/Decompression
Most of the axial rotation (60%) and some of the
flexion-extension (40%) and lateral bending of the
head occur in the UCS (C0-C2) [14, 30, 39]. The highly
specialized anatomy and osteoligamentous integrity
provides for a relatively paradoxical kinetic profile
with loose enough arrangement to allow for the
above-mentioned range of motion but tight enough to
prevent injury to spinal cord, nerves, and vertebral
arteries. When the integrity is interrupted for any reason (trauma, tumor, inflammation, and degeneration or
iatrogenic decompression), instability ensues. White
and Panjabi defined clinical instability as “the loss of
the ability of spine under physiologic loads to maintain
relationships between vertebrae in such a way that
there is neither initial nor subsequent damage to the
spinal cord or nerve roots, and in addition, there is neither development of incapacitating deformity nor
severe pain” [40]. The biomechanical profile of various
types of instability affecting the UCS is described in
Chaps. 2 and 3. Irrespective of the etiology of
mechanical instability (acute vs. chronic) of the UCS,
one has to be aware of the biomechanics involved in the
development of the condition in order to be able to
determine if a surgical construct is necessary to restore
stability and balance to the region, and if so, what kind
of construct can withhold the forces involved while
fusion is taking place.
P. Suchomel and O. Choutka, Reconstruction of Upper Cervical Spine and Craniovertebral Junction,
DOI: 10.1007/978-3-642-13158-5_5, © Springer-Verlag Berlin Heidelberg 2011
55
56
5 Basic Principles of Reconstruction Techniques
5.2 Construct Design
The concept of surgical spinal stabilization for a fracture was introduced in 1891 by Hadra [19] when he
operated on a fracture dislocation of a cervical spine in
a child showing progressive cord deterioration, using
wires wrapped around the spinous processes to stabilize the vertebral sector. This was a new concept for
the time of “holding broken or diseased bones together”
and was widely adapted until 1911 when spinal fusion
was first described as a treatment for Pott’s Disease
[3, 23]. Albee and Hibbs worked independently on
patients with Pott’s disease to design a method of spine
fusion. Albee used tibial cortical autograft and Hibbs
used spinous processes to produce surgical fusion.
Spinal constructs since then have changed significantly
but the concept of fixation and fusion remains the
mainstay of treatment of spinal instabilities, including
the UCS and CVJ. Screws, cages, and wiring/cable
techniques are all used in this region and must be able
to withhold the main forces with OA and AA joints,
flexion/extension, and rotation, respectively.
Multiple basic principles have been described for
application of metallic implants in the UCS. Most
commonly used implants at the CVJ include both anterior and posterior techniques and each individual clinical scenario determines the most appropriate approach.
Anterior implants include direct osteosynthetic screw
of the dens (lag) or cage constructs after odontoidectomy/corpectomy/spondylectomy or atlantoaxial transarticular screws. Posterior constructs can include
occipitocervical and atlantoaxial fixations through
means of various screw and rod/plate constructs or
direct osteosynthetic screws or wire/cable techniques
(Chap. 6). Buttressing, tension band, and neutralization principles usually apply to the constructs of the
CVJ [2] with the primary goal being immediate rigid
fixation so that favorable environment for bone fusion
is created.
for use in cervical trauma patients [8]. His plating
technique has gained wide popularity in the subaxial
spine in particular and offered immediate stability
without the use of external orthosis. The stability of an
anterior plate, however, is dependent on screw purchase within the vertebral bone. The initial Caspar
design was thought to be dependent on bicortical screw
purchase to prevent screw toggling. However, this
requirement was deemed unnecessary once locking
screw plates were developed and unicortical screws
were sufficient [6, 27]. Plate and screw constructs have
been used in orthopedic trauma management of various long and short bone fractures well before the use in
spine surgery and follow the tenets put forth by the
AO group in late 1950s [15]. The use of plate and
screw constructs in the ventral UCS is limited to C2-3
fusion when done for treatment of hangman’s fracture
[37], one can argue that certain anterior cage constructs
also follow buttressing principle when used in combination with anterior screws such as demonstrated by
the anterior clival-C3 construct in our patient with C2
chordoma resection [36] (Fig. 5.1).
Posteriorly, buttressing principle is applied with use
of plating systems with either screws or wires. Lateral
mass screw and plate construct offers similar rigidity in
5.2.1 Plate and Screw Constructs in the CVJ
Buttressing implants prevent axial deformity and are
placed on the side of load application [2]. An example
includes anterior cervical plate as developed by Caspar
Fig. 5.1 Sagittal CT demonstrating a complicated UCS cage/
screw construct after C2 spondylectomy. Anterior cage does not
only serve as the major load-bearing apparatus for the anterior
column but through its attachment to the clivus and C3 vertebral
body acts as a buttress
5.2 Construct Design
57
biomechanical in vitro studies to other types of posterior cervical constructs [12]. Even further, the authors
found no significant difference in rigidity between
combined anteroposterior and posterior only constructs.
It needs to be reiterated that the strength of a construct
is more dependent on the screw than the plate itself.
Magerl lateral mass screw technique is biomechanically superior to the Roy-Camille method, probably
due largely to the difference in screw length and trajectory [10]. Posterior cervical plate constructs are a safe
construct with low complication rate [21]. Nonetheless,
failure can be related to either the plate or the screw.
Screw bone interface (surface area) will influence the
pullout strength of any given, but a tapered or conical
screw configuration does not alter the pullout strength
[17]. Wellman et al. examined the safety and complications associated with lateral mass screws in their 43
patients [38]. Although, a proponent of bicortical
screw purchase in lateral mass screws to increase pullout strength, he concluded that bicortical screw purchase did not offer decrease biomechanical failure rate
(none in his series) and therefore, was not worth the
potential neurovascular risk. On the other hand, Heller
et al. argued that engaging the far cortex increases the
pullout strength by 28% [20] with less than 2% risk of
radiculopathy [21].
The issue of bicortical vs. monocortical screw purchase is a common discussion point when it comes to
the instrumentation of UCS and, perhaps, the key to
differentiation between a bicortical screw and bicortical penetrating screw needs to be made (Fig. 5.2). The
former offers the potential biomechanical advantages
of a bicortical purchase whereas the latter may, in addition, increase the chance of neurovascular injury. It
may be sensible to weigh the risk/benefit ratio in each
clinical scenario and consider the true need for bicortical screw purchase in a good quality bone versus not
achieving far cortex purchase in osteoporotic bone.
The bicortical screw discussion surrounds also occipital screw [22] and odontoid screw [35] placement
(indirectly with one vs. two screw conflict).
Anterior odontoid screw fixation is a well-accepted
method of direct, compressive, and osteosynthetic
construct that has evolved over time with multiple
variations all resulting in fracture line apposition,
alignment and compression, thus creating a favorable
bone-healing condition [1, 29]. All modifications of
anterior direct osteosynthetic odontoid screw, such as
fully threaded screw [7], cannulated K-wire guided
Fig. 5.2 Monocortical
screws are at risk of
toggling. Bicortical screw
purchase increase the
pullout strength in many
constructs. Penetrating
bicortical screws may,
however, increase the risk
of neurovascular injury.
Nearly bicortical screw
purchase may present an
alternative
screw [1], and double-threaded screw [9, 25] utilize the
same principle of fracture reduction, alignment, and
compression. However, even a good reduction is not
always feasible with anterior odontoid screw as up to
19% of cases end up malaligned [1]. The compressive
lag screw effect can be achieved through a differential
thread design, proximal overdrilling or a standard lag
screw design (Figs. 5.3 and 5.4). When using a fully
threaded screw, without overdrilling, the lag principle
does not apply and the screw simply becomes a
neutralizing/stabilizing one. This obviously creates
different bone-healing conditions than compressive
constructs. Neutralization does still provide stability
through minimization of torsional bending and shearing but may undergo indirect bone healing (i.e., formation of a callus rather than going through tissue
differentiation and resorption of bone surface [32].
Similar compressive, lag principle is applied to certain posterior techniques. Direct osteosynthesis of
hangman’s fracture as described by Judet [26] is a classic example (Fig. 12.19, Chap. 12). We have applied
this principle to a patient with a unilateral C1 lateral
mass fracture with fracture displacement (Figs. 7.5–
7.8, Chap. 7). A cannulated lag screw over a K-wire
was used to successfully reduce and fix this fracture
under CT guidance.