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86n 1996 H.D. Jho first introduced anterior cervical forami-notomy under the concept of functional spine surgery, inich compressive pathology is directly removed via an an-ior approach while the remaining disc and functioningtion unit are preserved.5 The original technique evolvedo several variations to achieve surgical goals efficiently andminimize surgical impact to the spinal column and func-ning motion unit.There is no appropriate terminology for this evolution ofgical procedures, which can be considered a continuingentific and artistic study to improve a particular surgicalatment for a specific condition. The simple, broad termrgery is defined in theWebster dictionary as (1) the treat-nt of disease, injury, or deformity by manual or instru-ntal operations, as the removal of diseased parts or tissuecutting; (2) an operation of this kind; (3) the branch ofdicine dealing with this. The suffix -ology is defined as

the science, doctrine, or theory of. Thus, we propose the termsurgiology to represent this pathoanatomical study in thepursuit of scientific or artistic knowledge to improve a par-ticular operative treatment.

We describe this surgiologic process for the anterior cer-vical foraminotomy technique. Originally, the nerve root wasapproached through the lateral portion of the uncovertebraljoint. A surgical entry hole was made at the uncovertebraljuncture, and a small hole was made from the medial portionof the uncovertebral joint toward the lateral portion to min-imize the risk of injury to the vertebral artery. This medial-to-lateral bone removal soon evolved to a lateral-to-medialapproach with bone removal starting just medial to the ver-tebral artery.

Surgical access to the target pathology was then tailoreddepending on the surgical trajectory. The trajectory from theskin incision to the surgical target in the sagittal plane of thecervical spine directs the location of the bone opening toaccess the target pathology directly and efficiently.

For an operation at C3-4, an anteroposterior surgical tra-jectory from the skin incision to the surgical target pointscephalad in a sagittal plane. Thus, the bone opening must beopened at the lower vertebra of the intervertebral disc; this iscalled the lower vertebral transcorporeal approach.

epartment of Neurological Surgery, Jho Institute for Minimally InvasiveNeurosurgery, Allegheny General Hospital, Drexel University College ofMedicine, Pittsburgh, PA.niversity of Illinois at Chicago College of Medicine, Chicago, IL.ress reprint requests to Hae-Dong Jho, MD, PhD, Professor of Neuro-logical Surgery, Director, Jho Institute for Minimally Invasive Neurosur-gery, Department of Neurological Surgery, Allegheny General Hospital,nterior Cervicaloraminotomy: Surgiologicvolution of Anterior Cervie-Dong Jho, MD, PhD,* and David H. Jho,

Following the concept of functional spine scervical foraminotomy in 1996. This proceduvia an anterior approach while preserving tseveral variations of the technique have beenlateral bone opening at the lateral aspect ofbone drilling from the medial margin of thepressive pathology involving the posterolateapproaches have been developed: the lowupper vertebral transcorporeal approaches. Etory made at the lateral portion of the cervicaThe anterior foraminoplasty technique can rnormal shape by eliminating bone spurs aloforamen. This article details the various techOper Tech Neurosurg 7:86-94 2005 Elsev

KEYWORDS: cervical disc herniation, cervicalpeSnyder Pavilion, 7C, 412 East North Avenue, Pittsburgh, PA 15212;DrJho@DrJho.com

1092-440X/05/$-see front matter 2005 Elsevier Inc. All rights reserved.doi:10.1053/j.otns.2004.11.001Disc Surgery

, the senior author introduced anteriorctly eliminates compressive pathologyctioning motion segment. Since then,loped. Instead of the original medial-to-ervical spine, a direct lateral-to-medialral artery has been adopted. For com-inal canal, three variations of surgicaltebral transcorporeal, transuncal, andariation uses a different surgical trajec-e to access the compressive pathology.truct the stenotic neural foramen to ae axis of the medial wall of the neurals for anterior cervical foraminotomy.. All rights reserved.

cervical stenosis, intervertebral disc,For a C5-6 operation, the surgical trajectory often alignsrpendicular to the sagittal plane of the spine. Thus, the

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Anterior cervical foraminotomy 87ne must be opened at the lateral portion of the uncinatecess; this is called the transuncal approach.For C6-7 or C7-T1, an anteroposterior surgical trajectoryints caudally to reach the surgical target in a sagittal planethe spine. Thus, the bone must be opened at the uppertebra; this is called the upper vertebral transcorporealproach. This latter approach can even be used for a C5-6eration if the skin incision is placed more cephalad thanal. This technique has most commonly been used forvical radiculopathy. The compressive pathology causingiculopathy, either soft disc herniation or spondylotic boners, is readily approachable when the bone is opened withaforementioned techniques.

When the neural foramen is narrowed by bone spur for-tion throughout the medial wall of the neural foramen,ne spurs must be removed along the longitudinal axis ofneural foramen. This is called anterior cervical foramin-lasty because the neural foramen will be restored to itsrmal shape after medial bone spurs are removed. The ver-al dimensions of the bone opening must be tailored to thee. However, the transverse thickness of the removed boneto 3 mm from the medial margin of the vertebral artery.

tails of these surgical techniques are described.

urgicaldications and Preparationrgical indications were the same as those for conventionalterior cervical discectomy. Patients often were seeking anernative surgical option after receiving a recommendationconventional anterior discectomy. Conservative treat-nt for a minimum of 6 weeks was first attempted unlessfound motor weakness or significant myelopathy was ev-nt. All patients underwent magnetic resonance imagingRI) preoperatively. Intraoperative somatosensory evokedtential (SSEPs) were monitored in all cases. Except for theliest patients who underwent surgery on an outpatientsis, all patients remained in the hospital for one night asndard protocol. All patients underwent follow-up MRId dynamic cervical spine radiographs 6 weeks aftergery.

urgical Techniquesitioningoperations were performed under general endotracheal

esthesia. Patient positioning is similar to that for conven-nal anterior discectomy.The head is kept straight without turning, and the neck ispt neutral without extension. If, however, MRI indicates aficiently large spinal cord canal, the neck can be extendedtly by placing a small bolster behind the shoulders. Whenspinal cord canal is narrowed, baseline SSEPs are re-ded before the head is positioned. SSEPs are monitoredtinuously until the end of surgery. The neck must besitioned carefully to prevent a position-induced injury tocervical spinal cord.

riations of Surgical Techniques

e original technique used in the anterior cervical micro-aminotomy was reported in 1996.5 In brief, the surgical

unjectry site at the anterior aspect of the spinal column is at thecovertebral juncture. A few millimeters width of the mosteral portion of the uncovertebral joint is removed from adial-to-lateral direction as a surgical conduit to the com-ssive pathology. However, this technique was soon mod-d because there is a natural tendency to removemore bonen required. Bone removal was often started too mediallym concern about potential vertebral artery injury. Open-the bone at the uncovertebral juncture does not alwaysduce optimal access to the target pathology because theival point of the surgical trajectory toward the pathologicalget is determined by the skin incision. Thus, technicaldifications soon followed.

wer Vertebral Transcorporeal Approache term lower vertebral transcorporeal approach refers tolocation of the bone opening at the lateral portion of theer vertebra of the intervertebral disc. For a C3-4 operationwhen the skin is inadvertently incised more caudally thanhould be at any cervical disc level, this technique is re-ired.The length of the transverse skin incision is 1 to 2 inches,pending on the size of the neck. The platysma can be splitgitudinally or divided transversely. Blunt dissection pro-ds medially to the sternocleidomastoid muscle and ca-id artery toward the anterior column of the cervical spine.r upper cervical spine surgery, intraoperative radiographsoften obtained to confirm the correct level of surgery. Forer cervical spine surgery, finger palpation of the surgical

atomy at the anterior column of the cervical spine and C6nsverse tubercle is often sufficient to identify the correctel.The longus colli muscle is split longitudinally to expose theeral portion of the spine. An anterior cervical retractortem is applied before the operating microscope is appliedmagnification. Endoscopic surgery has been performedthis operation; however, a specially designed endoscopeecessary.The medial portions of the transverse processes at thetral and caudal vertebrae are identified. The mostdial, upper 1- to 2-mm portion of the transverse pro-s at the lower vertebra is removed, and the vertebralery is identified. Using a 1- or 2-mm cutting drill bit, theperolateral 2- to 3-mm portion of the lower vertebra isilled posteriorly just medial to the vertebral artery (Fig.).A cephalad-inclined surgical trajectory leads the drillingard the target pathology posteriorly (Fig. 1B). Compres-e herniated soft disc or bone spurs are removed with mi-dissectors and various curved-up curettes. The nerve rootd lateralmost portion of the spinal cord are released frompression (Fig. 1C). Surgical closure is made at the

tysma. The skin is closed with absorbable 6-0 sutures in acuticular fashion.

nsuncal Approachhen the surgical trajectory from skin incision to targetthology is perpendicular to the sagittal plane of the cer-al spine, the bone must be opened at the anterolateraline along the line of the trajectory. In this case, the

cinate process lies along the perpendicular surgical tra-tory (Fig. 2A, B). Particularly for procedures at C4-5 or

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88 H. Jho and D.H. Jho-6, an ordinary skin incision at the upper- or midpor-n of the neck produces such a perpendicular surgicaljectory. Skin incision to bone exposure is performed asthe previously discussed approach. The medial 1 to 2of the most medial transverse processes at the upper

d lower vertebrae are removed, and the vertebral arterydentified. Then, the lateral uncinate process is dissectedm the vertebral artery. The most lateral 2-mm portionthe uncinate is drilled just medial to the vertebral arteryard the posterior longitudinal ligament. Once the pos-ior longitudinal ligament is exposed, compressive pa-logy, such as herniated soft disc or bone spurs, is ex-ed (Fig. 2C). Often the posterior longitudinal ligament

opened to expose the dura mater at the most lateralrtion of the spinal cord and proximal nerve root to

rem3-mtect hidden migrated disc fragments. The thin bony wallthe medial uncinate must not be damaged to maintainintegrity of the intervertebral disc (Fig. 2D). Surgicalsure is made with the aforementioned techniques.

per Vertebral Transcorporeal Approachis technique involves bone opening at the inferolateralrtion of the upper vertebra when the anteroposteriorrgical trajectory inclines caudally (Fig. 3A-D). Often it ised for C6-7 or C7-T1 surgery. However, it is also usedth other levels by placing the skin incision cephalad.e vertebral artery is exposed, and a 2-mm medial por-n of the transverse process of the upper vertebra is

Figure 1 Illustration showing the leftlower vertebral transcorporeal ap-proach. A small bone opening ismade at the superolateral aspect ofthe lower vertebra. The most medial2 mm of the transverse process at thelower vertebra is removed, and thevertebral artery is exposed. Next, thelateral 3 mm of the superolateral por-tion of the lower vertebra or the baseof the uncinate process (dotted area)is drilled toward the posterior longi-tudinal ligament (A). This techniqueis used when a foraminotomy is per-formed at a high cervical disc levelsuch as C3-4. The anteroposteriorsurgical trajectory, from the skin in-cision to the surgical target pathol-ogy, makes a cephalad incline asshown on a T2-weighted sagittal MRIof a patient with left C3-4 stenosis(B). Thus, the bone must be openedat the lower vertebra to reach the tar-get along the surgical trajectory. Sim-ilar techniques can be used if the skinis incisioned inadvertently caudal forsurgery at other cervical levels. Post-operative T2-weighted sagittal MRIobtained 6 weeks after left C3-4 andC4-5 anterior microforaminotomyconfirms good surgical decompres-sion (C).deoftheclo

UpThposuuswiThtiooved. The bone is opened at the inferolateral 2- tom portion of the upper vertebra by drilling toward the

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Anterior cervical foraminotomy 89sterior longitudinal ligament. The intervertebral end-te, at the anterior two-thirds of the intervertebral disc,st not be damaged. The surgical trajectory is directedard the pathological target only through the most pos-

Figure 2 Illustration showing the left transuncal approach. Tare removed, and the vertebral artery is defined. The verteblateral 2 to 3 mm of the uncinate process (dotted area) is dlayer of the medial uncinate process must be preserved tsurgical trajectory from the skin incision to the target pathspine for this technique (B). T2-weighted sagittal MRI obta(C). Postoperative anteroposterior radiograph shows the rcates the remaining left C6 uncinate process (D).ior portion. The rest of the procedure is the same asscribed for the other approaches.

exThterior Cervical Foraminoplasty.hen the nerve foramen is narrowed by spondylotic boneur formations from its origin at the spinal cord to its exithind the vertebral artery, the compressive pathology

dial 2 mm of the upper and lower transverse processery is dissected laterally to the uncinate process. Thetoward the posterior longitudinal ligament. The thintain the integrity of the intervertebral disc (A). Theust be perpendicular to the longitudinal axis of the

weeks postoperatively confirms good decompressionng portion of the uncinate process. The arrow indi-AnWspbe

he meral artrilledo mainology mined 6emainitends along the entire medial wall of the neural foramen.e nerve foramen must then be enlarged along its longi-

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90 H. Jho and D.H. Jhoinal axis. Because compressive pathology is usually lo-ed at the medial wall of the neural foramen, an anteriorproach toward the medial wall of the foramen is morepropriate than a posterior foraminotomy to remove thempressive pathology. In this case, when the medial bone

Figure 3 Illustration (A) and T2-weighted sagittal MRI (B) sused in the left upper vertebral transcorporeal approach.vertebra is removed, and the vertebral artery is defined. Thposteriorly (dotted area). The anterior two-thirds of the etrajectory from the skin incision to the target pathology incradiculopathy. Postoperative T2-weighted sagittal MRI shoPostoperative computed tomography scan, a coronal reconthe left C5 vertebra (D).urs are excised at the longitudinal axis of the neuralamen, the surgical procedure reshapes the neural fora-

lowven to its normal, large shape (Fig. 4A-E). Thus, the termterior foraminoplasty is more appropriate than anterioraminotomy.The 2-mm medial portion of the transverse process atvertebral artery foramen is removed at the upper and

e bone opening and surgical trajectory, respectively,edial 2 mm of the transverse process at the upperal 3 mm of the inferolateral upper vertebra is drilledte should not be damaged. Anteroposterior surgicalaudally in this technique, which is typically used forace of the surgical tract and good decompression (C).n, shows bone opening at the inferolateral portion ofmeanfor

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Anterior cervical foraminotomy 91eral 2-mm of the uncinate process are drilled toward thesterior longitudinal ligament. Drilling must be directedng the nerve passage from pedicle to pedicle to obtainmplete decompression in the vertical dimension. Whenposterior longitudinal ligament is exposed, posterior

ne spurs are excised in front of the lateral spinal cord. Ifinal cord decompression is required, bone spurs ante-r to the spinal cord are excised through a foramin-lasty hole. The posterior longitudinal ligament is ex-ed, and the dura mater is exposed from pedicle todicle. Sometimes the superior portion of the inferiordicle must be shaved when the vertical dimension of theural foramen is narrowed. Stenosis along the verticalension of the neural foramen is relatively common in

Figure 4 Illustration showing an anterior cervical foraminopportion of the transverse processes at the upper and lowerstenosis. The bone spurs along the medial wall of the neuhigh-speed drill (A). Preoperative left oblique radiograpradiculopathy shows foraminal stenosis with bone spurradiograph shows the enlarged neural foramina (C). T2-preoperatively (D) and the widely decompressed neural focervical spine of elderly patients. Surgical closure is thee as previously described.

phcoostoperative Managementhough our earliest patients underwent outpatient sur-ry, we now prefer to keep all patients one night in thespital as standard protocol. Postoperative pain is rela-ely minor, and most patients are prescribed oral nar-tic analgesics (although some decline to take them).tients are allowed to resume their normal routine imme-tely after surgery. Cervical collars are neither necessaryr used. The surgical wound is exposed to the air the dayer surgery, and exercise or showering is allowed thext day. Contact sports activities and heavy weight-liftingprohibited for 4 to 6 weeks. Patients can return toce work within a few days, but they cannot resume a

The vertebral artery is defined by removal of a 2-mmrae. This technique is used for spondylotic foraminalamen along its longitudinal axis are trimmed with ae cervical spine in a patient with left C6 and C7tion at C5-6 and C6-7 (B). Postoperative obliqueed axial MRIs at C5-6 show left foraminal stenosis6 weeks after surgery (E).PAltgehotivcoPadianoaftneareoffi

lasty.vertebral forh of thformaweightramenysically laborious job for 4 to 6 weeks. Postoperativentrast-enhanced MRI (Fig. 5A-D) and dynamic radio-

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92 H. Jho and D.H. Jhophs are routinely obtained 6 weeks after surgery (Fig.-C).

esultse previously reported 104 patients (45 men, 59 women;dian age, 46 years; age range, 26-74 years) who met thelowing study criteria: unilateral cervical radiculopathy thatled to respond to at least 6 weeks of conservative treatmentat least 4 weeks if patients exhibited profound motor

akness), imaging studies confirming pathoanatomic fea-es corresponding to clinical symptoms, no previous cervi-spine surgery, and no significant spondylotic stenosissing spinal cord compression.Compressive pathology included spondylotic spurs in 44tients (42.3%), soft disc herniation in 54 patients (51.9%),d a combination of the two in 6 patients (5.8%). The du-

Figure 5 Preoperative T2-weighted axial MRIs show a C5excellent decompression with left C5-6 anterior microforaweeks after surgery (B). T2-weighted sagittal MRIs show noion of symptoms ranged from 4 weeks to 156 monthsean, 17.6 months). Follow-up ranged from 12 to 86

hissitinths (median, 36 months). In addition to radiculopathy,operative symptoms included severe neck pain in 83 pa-nts (79.8%) and significant occipital head pain in 11 pa-nts (10.6%).Surgical results were graded as follows: excellent,mplete resolution of all symptoms; good, relief of ra-ulopathy but occasional minimal to mild residual non-icular discomfort; fair, mild residual radiculopathyth or without mild to moderate residual nonradicularcomfort; poor, significant radicular symptoms with orthout nonradicular discomfort; unchanged; ororse. Of the 104 patients, 83 (79.8%) had excellenttcomes, 20 (19.2%) had good outcomes, and one (1%)d a fair outcome. No patient had a poor or unchangedtcome.One patient developed discitis, which resulted in sponta-ous fusion at the operated level after antibiotic treatment;

c herniation and foraminal encroachment (A) andmy via an upper vertebral trancorporeal approach 6es in the disc height before (C) and after (D) surgery.mopretietie

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-6 disminotochangradiculopathy resolved well. One patient developed po-on-related hemiparesis, which resolved in 6 weeks. Two

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Anterior cervical foraminotomy 93tients developed transient Horners syndrome, which re-ved in 6 weeks.14

iscussioniginally, anterior cervical foraminotomy was a new surgi-concept in anterior cervical disc surgery and involved newgical techniques utilizing access through the uncoverte-l joint.5 Although conventional anterior cervical disc sur-y has evolved in the last 50 years into complete removal ofintervertebral disc with bone graft fusion and metal im-nt, the core concepts of discectomy and bone fusion haveanged little.19 However, to preserve the motion unit whileieving direct removal of the compressive pathology,nctional spine surgery was proposed with a surgical ap-ach to the cervical disc herniation through an anterolat-l route. In the original description, the most lateral 5 mmthe uncovertebral juncture was removed to access thepressive pathology. The nerve root was then widely de-pressed from its origin at the spinal cord to its exit be-d the vertebral artery. Although lateral approaches to thevical spine have been reported previously,1,4,18,20 anteriorvical microforaminotomy under the concept of func-nal spine surgery was completely new. The evolution ofr surgical techniques is discussed elsewhere.6-16

The intervertebral disc of the cervical spine in a sagittalne inclines cephalad in an anteroposterior direction.us, when the original surgical technique is utilized, thegical approach usually reaches the upper portion of thedicle and caudal portion of the surgical target. To compen-e for this aberration, the surgical trajectory must inclinehalad and proceed posteriorly when the originally de-ibed foraminotomy is adopted. To reach the surgical targetciently, the anterior bone opening of the anterior forami-

Figure 6 Flexion (A) and extension (B) dynamic radiographsthe preservation of motion at C5-6. A left-sided anterior mitranscorporeal approach. Anteroposterior radiograph reveaC5 vertebra (C).tomy must be moved cephalad. The skin opening alsost align with the surgical trajectory for this foraminotomy.

allif sus, the skin incision must be placed much more cephaladn it is in a conventional anterior discectomy.In the anterior foraminotomy, the anterior bone is openedthe most lateral upper vertebral body to reach the surgicalget naturally when the foraminotomy hole is advancedsteriorly perpendicular to the longitudinal axis of the spi-l column. With this technique, only the posterior one-rd portion of the surgical trajectory involves the interver-ral juncture, which is actually the posterior portion of thecovertebral juncture, which is usually the site of the com-sion. This technique consists of opening the bone at theper vertebrae; thus, the technique is termed the uppertebral transcorporeal approach.When an anteroposterior surgical trajectory becomes per-ndicular to the longitudinal axis of the spine, the bonest be opened at the lateral portion of the uncinate; thus,technique is called a transuncal approach. When thegical trajectory inclines cephalad, the lower vertebralnscorporeal approach must be adopted with the boneened at the lateral lower vertebra. The medial 2-mm por-n of the vertebral artery is exposed tominimize the amountbone removed at the vertebral body. When a narrow neu-foramen requires reconstruction into a large normalpe, anterior foraminoplasty is performed with direct re-val of the medial bone spurs along the longitudinal axis ofneural foramen. Others have reported their experiences

th this technique.2,3,17

Although the risks of anterior foraminotomy surgery haveen minimal in our experience, there are many possibleious complications. Vertebral artery injury, recurrent discrniation, and spinal instability are major concerns. Verte-l artery injury can cause an immediate or delayed brain-m stroke. Such an injury must be repaired surgically. Fur-r proximal and distal exposure of the vertebral artery

cervical spine obtained 6weeks after surgery confirmminotomywas performed through an upper vertebraall bone opening at the left inferolateral portion of theupver

pemuthesurtraoptioofralshamothewi

beserhebrastetheows direct repair of the artery. Spinal instability can occurubstantial bone is removed.3 When patients complain of

significant neck pain after surgery, spinal instability must beconsidered, and spinal fusion may be necessary. When theintervertebral disc is violated substantially, recurrent discherniation can occur through the surgical defect of the annu-lus. The size of the foraminotomy hole must be minimal.Horners syndrome, hoarseness, infection, nerve root or spi-nal cord damage, wrong-level operation, epidural bleeding orhematoma, cerebrospinal fluid leakage, wound hematoma,or any other complications associated with conventional an-terior cervical discectomy are also possible complications as-sociated with this operation. Because of these potential seri-ous complications, surgeons must be well trained to performthis particular type of surgery.

AcknowledgmentThe authors thank Mi-Ja Jho, BE, and Robin Coret, BA, fortheir assistance in preparing this manuscript.

References1. George B, Zerah M, Lot G, et al: Oblique transcorporeal approach to

anteriorly located lesions in the cervical spinal canal. Acta Neurochir(Wien) 121:187-190, 1993

2. Grundy PL, Germon TJ, Gill SS: Transpedicular approaches to cervicaluncovertebral osteophytes causing radiculopathy. J Neurosurg (Spine1) 93:21-27, 2000

3. Hacker RJ, Miller CG: Failed anterior foraminotomy. J Neurosurg(Spine 2) 98:126-130, 2003

4. Hakuba A: Trans-unco-discal approach: A combined anterior and lat-

5.

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spondylotic cervical myelopathy: Technical note. Neurosurg Focus1:1-11, 1996

8. Jho HD: Spinal cord decompression via microsurgical anterior forami-notomy for spondylotic cervical myelopathy. Minim Invas Neurosurg40:124-129, 1997

9. Jho HD: Microsurgical anterior cervical foraminotomy for radiculopa-thy: A new approach to cervical disc herniation. Minimally invasivetechniques of spinal surgery. Neurosurg Focus 4:1-6, 1998

10. Jho HD: Anterior microforaminotomy for cervical radiculopathy: Discpreservation technique, in Rengachary SS, Wilkins RJ (eds): Neurosur-gical Operative Color Atlas. Baltimore, Williams & Wilkins, 1998, Vol7, pp 43-52

11. Jho HD: Treatment of spondylotic cervical myelopathy via anteriorforaminotomy, in Camins MB, Loftus CM, Batjer HH (eds): CervicalSpinal Stenosis, Techniques in Neurosurgery. Philadelphia, Lippincott-Raven, 1999, pp 124-132

12. Jho HD, Ha HG: Anterior cervical microforaminotomy. Kang JD, Fu F(ed): Current Techniques in Cervical Spine Surgery, Operative Tech-niques in Orthopaedics. Philadelphia, WB Saunders, 1998, Vol 8, pp46-52

13. Jho HD, Ha HG: Anterolateral approach for spinal cord tumors. MinimInvas Neurosurg 42:1-6, 1999

14. JhoHD, KimWK, KimMH: Anterior microforaminotomy for treatmentof cervical radiculopathy: Part 1Disc-preserving functional cervicaldisc surgery. Neurosurgery 51(suppl 2):46-53, 2002

15. Jho HD, MH Kim, WK Kim: Anterior cervical microforaminotomy forspondylotic cervical myelopathy: Part 2. Neurosurgery 51(suppl 2):54-59, 2002

16. Jho HD: Editorial: Failed anterior cervical foraminotomy. J Neurosurg(Spine 2) 98:121-125, 2003

17. Johnson JP, Filler AG, McBride DQ, et al: Anterior cervical foramin-otomy for unilateral radicular disease. Spine 25:905-909, 2000

18. Lesoin F, Biondi A, Jomin M: Foraminal cervical herniated disc treated

19.

20.

94 H. Jho and D.H. Jhoeral approach to cervical discs. J Neurosurg 45:284-291, 1976Jho HD: Microsurgical anterior cervical foraminotomy: A new ap-proach to cervical disc herniation. J Neurosurg 84:155-160, 1996Jho HD: Decompression via microsurgical anterior foraminotomy forcervical spondylotic myelopathy. J Neurosurg 86:121-126, 1997Jho HD: Decompression via microsurgical anterior foraminotomy forby anterior discoforaminotomy. Neurosurgery 21:334-338, 1987Sampath P, Bendebba M, Davis JD, et al: Outcome in patients withcervical radiculopathy. Prospective, multicenter study with indepen-dent clinical review. Spine 24:591-597, 1999Verbiest H: A lateral approach to the cervical spine: Technique andindications. J Neurosurg 28:191-203, 1968

Anterior Cervical Foraminotomy: Surgiologic Evolution of Anterior Cervical Disc SurgerySurgical Indications and PreparationSurgical TechniquePositioningVariations of Surgical TechniquesLower Vertebral Transcorporeal ApproachTransuncal ApproachUpper Vertebral Transcorporeal ApproachAnterior Cervical Foraminoplasty

Postoperative ManagementResultsDiscussionAcknowledgmentReferences