Overview
Anterior discectomy and interbody fusion has wide application and produces excellent results in virtually all forms of cervical disc disease and spondylosis (Campbell). The levels most often involved by degeneration are, in descending order, C5-6, C6-7 and C4-5. Correlation of symptoms with imaging is essential: 14% of asymptomatic people younger than 40 years and 28% of those older than 40 have significant abnormalities on MRI (Campbell).
Clinical Evaluation (Campbell)
Radiculopathy by root
Root (disc) | Sensory deficit | Motor weakness | Reflex |
|---|---|---|---|
C5 (C4-5) | Upper lateral arm and elbow | Deltoid, biceps (variable) | Biceps (variable) |
C6 (C5-6) | Lateral forearm, thumb, index finger | Biceps, ECRL/ECRB | Biceps, brachioradialis |
C7 (C6-7) | Middle finger (variable) | Triceps, wrist flexors (FCR), finger extensors (variable) | Triceps |
C8 (C7-T1) | Ring and little fingers, ulnar palm | Interossei, finger flexors, FCU (variable) | None |
T1 | Medial elbow | Interossei | None |
Spurling test (head turned to the affected side, neck extended, downward pressure) is 95% sensitive and 94% specific for cervical root pathology; the shoulder abduction relief sign helps distinguish cervical from shoulder pathology.
Rule out distal entrapment (thoracic outlet, carpal and cubital tunnel syndromes).
Myelopathy: poorly localized pain, Lhermitte-type symptoms, clumsy hands, gait disturbance and difficulty with tandem gait (often the first symptoms); signs include hyperreflexia, sustained clonus, Babinski and Hoffmann signs or an inverted radial reflex.
Imaging (Campbell)
Plain radiographs cannot identify the level of neural compression; MRI or CT myelography is strongly recommended for planning.
Indications (Campbell)
Failure of nonoperative pain management (the primary indication in most patients); 70-80% of patients with symptomatic disc herniation, including some with nonprogressive weakness, respond to nonoperative care.
Increasing and significant neurologic deficit.
Cervical myelopathy, which predictably progresses.
Soft lateral discs are easily removed posteriorly (foraminotomy); soft central discs and hard discs (central or lateral) are probably best treated anteriorly.
Best results: single-segment discectomy and fusion for definite root impairment or cord compression. Fusions of more than two segments for pain alone give fair or poor results.
When large osteophytes or ossified posterior longitudinal ligament compress the cord, especially with T2 cord signal change, direct anterior decompression gives superior results.
The authors rarely operate without radicular pain plus objective neural compression or deficit.
Preoperative Planning (Campbell)
Choose the side by surgeon comfort. Evaluate the vocal cords and swallowing in patients with dysphagia, dysphonia or prior neck surgery; if a cord is paralyzed, approach from the same side as the paralysis.
Somatosensory and motor-evoked potential monitoring is useful in myelopathy or cord signal change.
Surface landmarks: hyoid C3, thyroid cartilage C4-5, cricoid cartilage C6.
Technique 45.6: Smith-Robinson Anterior Cervical Discectomy and Fusion (Campbell)
Exposure
Position supine with a small roll between the scapulae.
Apply a head halter (5-10 lb traction if desired) when anterior plating is planned; otherwise distraction pins and the retractor can open the disc space.
Rotate the head slightly away from the approach side.
Mark the incision, preferably in an existing skin crease. A transverse incision can be used even for three-level corpectomy if well placed; otherwise use the sternocleidomastoid border.
Divide the skin and dissect the subcutaneous layer off the platysma to mobilize the wound.
Lift and divide the platysma vertically near the midline.
Develop the interval just medial to the sternocleidomastoid; palpate the carotid sheath and the omohyoid.
Retract the omohyoid caudally for levels above C5 or cranially for C5 and below.
Sharply divide the pretracheal fascia medial to the carotid sheath; avoid dissection lateral to the sheath (sympathetic chain).
Develop the prevertebral space bluntly, medially and posteriorly.
With handheld retractors medially, expose the paired longus colli; elevate them subperiosteally with bipolar cautery and small elevators.
Obtain a localization radiograph with a bent spinal needle in the disc space before excising any disc.
Ligate superior or inferior thyroid vessels if they limit exposure.
Do not elevate the longus colli as far as the transverse processes (sympathetic chain, vertebral artery), but expose the anterior uncovertebral joints on both sides.
Place self-retaining blades deep to the longus colli.
Distraction pins may be used for single-level discectomy; avoid them in multilevel cases or when screws are planned, because pin-site microfracture reduces screw purchase.
Discectomy and decompression
Incise the anterior annulus with a No. 11 blade, cutting toward the midline from each uncovertebral joint.
Remove the annulus and the anterior one-half to two-thirds of the disc with pituitary rongeurs and curettes, exposing each uncinate process (slight upward curve of the caudal endplate), which marks the safe lateral limit (vertebral artery).
Use an operating microscope for removal of the posterior disc, osteophytes or posterior longitudinal ligament (PLL).
Burr the anterior lip of the cephalad vertebra flush with its midbody subchondral bone to create a flat surface and improve visualization.
If a soft fragment is found without violation of the PLL, further canal exploration is not warranted.
Perform foraminotomy with small Kerrison rongeurs if needed; if a PLL defect is found, enlarge it and explore for fragments.
If complete PLL removal is planned, complete any corpectomies first (lateral gutters at the uncinate processes, midline bone removal to posterior cortex, bipolar cautery only near neural tissue).
Lift the PLL with a small blunt hook and open the epidural space with a 1-mm Kerrison; remove it entirely if needed, freeing it bluntly from the dura. Preserve the PLL when possible to enhance stability.
A small blunt probe should pass easily anterolaterally after foraminotomy.
Endplate preparation and grafting
Remove all cartilage while preserving subchondral bone; make the decompression the width of the endplate between the uncinates, with parallel endplates. Preserve the anterior cortex of the adjacent vertebrae.
Measure the AP depth at each endplate: the graft depth should be 3-4 mm less than the shorter endplate, so it can be recessed about 2 mm anteriorly without encroaching on the canal. Measure height with and without traction so the graft is under compression.
Harvest a tricortical iliac crest graft with a small oscillating saw.
Fashion the graft, place the cancellous surface posteriorly, bevel the posterior margins slightly and impact it under traction so the cortical portion is recessed 1-2 mm behind the anterior vertebral cortex, leaving 2 mm of space between the graft and the canal.
Release traction and check the fit with a Kocher clamp; repeat at each level.
Apply an anterior cervical plate if needed with all traction released.
Confirm graft and hardware position radiographically.
Close the platysma over a soft closed-suction drain, close subcutaneous tissue and skin, and apply a cervical orthosis before extubation.
Graft biomechanics (Campbell)
The Smith-Robinson horseshoe tricortical graft provides the greatest stability and least risk of extrusion compared with Cloward dowel and Bailey-Badgley slot grafts; a keystone graft increases contact area by 30%.
Postoperative Care (Campbell)
Out of bed on the day of surgery; remove the drain on the first postoperative day.
Orthosis for 2 weeks after discectomy and 8-12 weeks after corpectomy, depending on compliance and graft appearance. An external orthosis has not been shown to improve fusion in one- and two-level ACDF; a soft collar is used for comfort.
Airway obstruction is rare but can occur 1-36 hours after surgery; maximal swelling occurs at 24-48 hours. The authors monitor patients for 6 hours before discharge.
Complications (Campbell)
Complication | Notes |
|---|---|
Wrong level | Mandatory localization film with a metal marker that shows C1 or C2; avoid violating a disc until the level is confirmed |
Recurrent laryngeal nerve palsy | Retraction injury; deflating and reinflating the endotracheal tube cuff after retractor placement may reduce compression |
Esophageal or pharyngeal injury | Retractor injury; locking plates reduce screw back-out and perforation |
Sympathetic chain injury | Stay medial to the carotid and in correct planes |
Dural tear or cord compression | Use sharp, small angled curettes and Kerrison rongeurs with control |
Graft extrusion | Mostly with posterior instability (fracture-dislocation); rare in degenerative disease |
Pseudarthrosis | 3-7% single level; 12-18% two-level autograft without plate; usually at the caudal segment; symptomatic nonunion is best managed by posterior fusion. Avoid multilevel allograft without plating |
References
Thompson KM. Degenerative disorders of the cervical spine. In: Azar FM, Sawyer JR, Throckmorton TW, eds. Campbell's Operative Orthopaedics. 15th ed. Philadelphia: Elsevier; 2026. Chapter 45, Technique 45.6.
Campion CE. Approaches to the cervical, thoracic, and lumbar spine. In: Azar FM, Sawyer JR, Throckmorton TW, eds. Campbell's Operative Orthopaedics. 15th ed. Philadelphia: Elsevier; 2026. Chapter 44, Technique 44.8.