Gold standard surgical approach for cervical degenerative disease with neural compression - Smith-Robinson technique with contemporary instrumentation | intermediate
- ACDF is the gold standard for single- and two-level cervical radiculopathy or myelopathy refractory to conservative care, with 90 percent excellent or good outcomes for radiculopathy.
- C5-6 is the commonest level (about 60 percent), then C6-7 (25 percent). Fusion rates with anterior plating: single-level 95-98 percent, two-level 90-95 percent, three-level 85-90 percent.
- A left-sided approach is preferred - the recurrent laryngeal nerve is more predictable (1-2 percent injury versus 5-8 percent on the right, where a non-recurrent variant occurs in 0.3-0.6 percent).
- The whole operation hinges on the avascular plane between the carotid sheath (lateral) and the visceral column (medial), developed by blunt finger dissection.
- Complete discectomy down to the posterior longitudinal ligament is essential - incomplete decompression is the commonest cause of persistent symptoms.
- The longus colli defines the safe lateral limit; the vertebral artery lies 3 mm lateral to the uncovertebral joint and is injured during over-lateral dissection (0.3-0.5 percent).
When & Why
Indications Absolute
- Progressive cervical myelopathy with cord compression (modified JOA score decline).
- Cervical radiculopathy failing 6-12 weeks of conservative management with MRI-confirmed nerve root compression.
- Cervical kyphotic deformity with anterior column deficiency requiring reconstruction.
- Post-traumatic cervical instability (facet disruption, anterior longitudinal ligament or disc injury).
- Anterior cervical tumour or infection requiring corpectomy and reconstruction. Relative
- Radiculopathy with concordant imaging in a high-demand patient.
- Multilevel spondylosis with predominant axial neck pain (controversial - consider arthroplasty).
- Soft disc herniation with persistent radicular symptoms despite optimised non-operative care.
- Symptomatic adjacent-segment disease following a prior fusion. Contraindications
- Absolute: active systemic infection, severe osteoporosis (DEXA T-score less than -3.5), medical instability.
- Relative: greater than 3 levels (consider a hybrid construct), smoking (2.7x pseudarthrosis risk), significant baseline dysphagia, ankylosing spondylitis (avoid operating through a fused segment). Preoperative planning Imaging and patient optimisation drive both safety and fusion:
- MRI: T2 cord signal change (myelomalacia) predicts a poorer prognosis; grade disc hydration and foraminal stenosis.
- CT: assess ossification of the posterior longitudinal ligament (about 40 percent of Asian populations), uncovertebral hypertrophy and facet arthropathy.
- Flexion-extension radiographs: document instability (greater than 3 mm translation or greater than 11 degrees angulation).
- CTA: for revision surgery (scar distorts anatomy) or a suspected vascular anomaly.
- Optimisation: smoking cessation for at least 8 weeks (roughly 3x fusion-rate improvement), diabetic HbA1c less than 7.5 percent, BMI optimisation, stop NSAIDs 1 week preoperatively. Graft and instrumentation selection
Gold-standard biologics with about 98 percent single-level fusion, but 20 percent donor-site pain, a lateral femoral cutaneous nerve risk, and added operative time.
Equivalent fusion with anterior plating (about 95 percent), no donor morbidity; 8-12 percent subsidence.
Contemporary standard - 92-95 percent fusion, radiolucent (MRI/CT friendly), 5-8 percent subsidence.
rhBMP-2 (off-label in the cervical spine) achieves about 98 percent fusion but roughly doubles dysphagia from soft-tissue swelling and carries an 18 percent heterotopic ossification rate - reserve for revision pseudarthrosis and counsel the patient on the FDA caution. Anterior plating reduces pseudarthrosis at three levels from roughly 44 percent to 8 percent and preserves lordosis, and is mandatory for two or more levels. Zero-profile devices (a cage with integrated screws) roughly halve early dysphagia (about 12 percent versus 28 percent at 3 months). Consent specifically for hoarseness or recurrent laryngeal nerve palsy (1-8 percent), dysphagia and dysphonia (30-70 percent early, 10-20 percent at 1 year), C5 palsy with deltoid or biceps weakness (4-7 percent), vertebral artery injury or posterior circulation stroke (0.3-0.5 percent), spinal cord injury (less than 0.1 percent), postoperative haematoma and airway compromise (0.5-2 percent), esophageal injury (0.1-0.25 percent), pseudarthrosis, and adjacent-segment disease. Setup. Supine with a shoulder roll to extend the neck, head in neutral rotation, slight reverse Trendelenburg, arms tucked and padded; left-sided approach; C-arm on the patient's right. Gardner-Wells tongs or a horseshoe headrest for controlled extension is optional.
The Operation
The goal is to expose the cervical spine through the Smith-Robinson anterior approach, remove the diseased disc and any posterior osteophytes to decompress the cord and nerve roots, restore disc height and lordosis with an interbody graft, and stabilise the segment with an anterior plate. The exposure - finding and maintaining the correct avascular plane - is the heart of the operation, and is laid out in full in the steps below (and on the Smith-Robinson anterior cervical spine approach page).
Operative sequence
- Supine with a shoulder roll to extend the neck (opens the disc spaces, restores lordosis); head in neutral rotation (rotation distorts anatomy and stretches the vertebral artery); slight reverse Trendelenburg; arms tucked and padded for lateral C-arm access.
- Approach side - left preferred. The left recurrent laryngeal nerve has a more predictable course (injury 1-2 percent versus 5-8 percent on the right, where it loops under the subclavian and ascends obliquely). Choose the right only if the surgeon is left-handed or there is prior left-neck surgery or radiation.
- Surface landmarks for the incision: C2-3 angle of mandible; C3-4 thyroid cartilage superior margin; C4-5 cricoid cartilage; C5-6 omohyoid crossing or carotid tubercle (Chassaignac, on the C6 transverse process); C6-7 two fingerbreadths above the suprasternal notch; C7-T1 at the notch.
- C-arm on the patient's right; the surgeon operates from the right for a left-sided approach.
- Transverse incision along the skin crease (Langer lines), 4-5 cm, centred on the palpated level (4 cm for one level, 5 cm for two). Infiltrate with 1:200,000 epinephrine for haemostasis.
- Divide the platysma in line with its fibres; raise subplatysmal flaps about 1 cm superiorly and inferiorly with Metzenbaum scissors to gain exposure.
- Pearl: place a two-level incision at the mid-level (for example a C5-6 incision for a C5-7 fusion) so it extends equally in both directions; an incision placed exactly at one disc level limits inferior extension.
- At risk: the external and anterior jugular veins crossing the field - ligate branches or divide between clips.
- Divide the investing layer of the deep cervical fascia along the medial border of SCM; palpate the carotid pulse laterally and the trachea medially.
- Insert the index finger and develop the plane by gentle spreading between the carotid sheath (laterally) and the visceral column (medially) - the correct plane is essentially bloodless. Sweep superiorly and inferiorly down to the prevertebral fascia.
- Retract the omohyoid (crossing obliquely at C5-6) superiorly or divide it between clips; ligate crossing thyroid vessels (superior thyroid artery at C4-5, middle thyroid vein at C6).
- Pearl: blunt finger dissection is safest - it respects natural tissue planes and warns of aberrant anatomy. If the plane is difficult you are too anterior (in the strap muscles) or too lateral (against the carotid).
- At risk: the recurrent laryngeal nerve in the tracheoesophageal groove (never retract in the midline), the sympathetic chain on the prevertebral fascia (Horner syndrome), and the esophagus (perforation with forceful medial retraction).
- Incise the prevertebral fascia vertically in the midline with monopolar cautery; elevate the longus colli bilaterally off the anterior vertebral bodies for about 1.5 cm to accept the retractor blades.
- Place self-retaining retractors (Caspar or Cloward) with deep 15 mm toothed blades under the longus colli - the teeth engage vertebral body bone, not disc. Retract the esophagus medially with a smooth handheld blade.
- The longus colli defines the safe lateral limit of the whole dissection.
- Pearl: retractor teeth must grip bone, not disc (migration risks cord injury); intermittently deflate the endotracheal cuff to reduce total esophageal compression.
- At risk: the vertebral artery 3 mm lateral to the uncinate (torrential bleeding, stroke), the cord (a blade slipping posteriorly through the disc), and the esophagus (pressure necrosis after about 120 minutes).
- Insert a 21G spinal needle into the centre of the disc under direct vision (only 3-4 mm deep); obtain a lateral C-arm and count from C2 (prominent spinous process) proximally and C7 (first vertebra below the shoulder) distally - triangulate.
- Mark the operative level with a cautery scratch on the vertebral body; save the image for documentation.
- Never event: wrong-level surgery is prevented only by systematic intraoperative verification, never by preoperative skin marking alone. C3-4 and C4-5 look alike on the lateral view.
- Mark a rectangular window in the anterior annulus (about 14 mm wide - vertebral body width minus 2 mm each side) and incise a three-sided flap hinged inferiorly.
- Remove the nucleus pulposus with pituitary rongeurs (grasp and twist), working centrally then laterally and posteriorly; remove the cartilaginous endplates with 20 and 30 degree curettes to bleeding subchondral bone, preserving the bony endplate.
- Pearl (rate-limiting for symptom relief): complete the discectomy to the posterior annulus - pass a ball probe to confirm it is palpable circumferentially. Incomplete removal is the commonest cause of persistent radiculopathy and lowers fusion rates.
- At risk: the vertebral artery with lateral dissection beyond the uncinate, endplate violation (subsidence and kyphosis), and retained disc fragments.
- Identify the glistening posterior longitudinal ligament; resect posterior osteophytes from the vertebral bodies above and below with upbiting 2 mm Kerrison rongeurs (jaws facing away from the cord - never downbite).
- For uncovertebral spurs compressing the root, drill at a 45 degree medial trajectory with a 3 mm diamond burr under direct vision, protecting the vertebral artery 3 mm lateral; copious irrigation clears bone dust.
- For myelopathy, resect the PLL midline until dural pulsations return; for radiculopathy, foraminotomy is adequate when a ball probe passes freely into the foramen and you "see blue sky" (epidural veins).
- At risk: the cord (upbiting technique mandatory), a dural tear with CSF leak, the vertebral artery (limit drilling to the medial half of the foramen), and the nerve root.
- Place Caspar distractor pins 2 cm lateral to the midline (in the safe zone medial to the uncinate); distract 1-2 mm only to restore disc height and tension the ligaments.
- Prepare parallel endplates to bleeding bone; measure the anterior, middle and posterior heights with calibrated trial spacers.
- Pearl: restore physiological height (about 5-6 mm at C5-6), not more - over-distraction risks a C5 palsy from root tethering and facet fracture. Select a graft 1 mm larger than the posterior height to restore 4-6 degrees of lordosis per level.
- Choose a structural allograft, iliac-crest autograft, or a lordotic PEEK or titanium cage packed with local bone or demineralised bone matrix; contour 4-6 degrees of lordosis.
- Impact under direct vision to a central position, flush with the anterior vertebral cortex or recessed 2 mm; remove the distractor - ligamentotaxis compression should hold the graft stable.
- At risk: graft extrusion if undersized or anterior (dysphagia, esophageal erosion), cord compression if oversized (emergency removal), and subsidence if the endplate is violated.
- Select a plate that spans from one vertebral body above to one below; position it midline, within 5 mm of the superior disc.
- Four screws (two per vertebra), angled away from the adjacent disc (cranial screws cranially, caudal screws caudally, 12-15 degrees), typically 14 mm; aim for bicortical purchase without excess length (greater than 18 mm risks the canal). Lock the screws to prevent backout.
- Pearl: zero-profile devices (a cage with integrated screws) roughly halve early dysphagia - consider them at C5-6 and C6-7. Variable-angle screws accommodate a kyphotic deformity.
- Lateral view: correct level, graft within the disc space, restored height and lordosis, plate within 5 mm of the disc, screws not violating the adjacent disc or canal; trace the posterior vertebral body line (it should be smooth, with no step-off).
- AP view: graft centred, screws symmetric about the midline, no lateral graft migration. Save both views for documentation and adjust before closure if anything is off.
- Remove the retractors; meticulous bipolar haemostasis (avoid monopolar near the esophagus); irrigate with 1-2 L of saline. Place a 10Fr Blake drain deep to platysma for multilevel or extensive cases (removed on POD1).
- Close the platysma with 2-0 Vicryl, the subcutis with 3-0 Vicryl (buried knots), and the skin with a 4-0 Monocryl subcuticular suture plus Steri-Strips; avoid circumferential dressings (neck compression risks the airway).
- At risk: a postoperative haematoma (an airway emergency, 0.5-2 percent), an unrecognised esophageal injury (delayed perforation at 48-96 hours), and a drain eroding the esophagus (never place a drain midline on the esophagus).
The longus colli is the safe lateral boundary of the entire exposure. The vertebral artery lies about 3 mm lateral to the uncovertebral joint within the transverse foramen (entering at C6 in 90 percent of people, anomalous in 5 percent). Limit all lateral dissection to the medial border of the uncinate, direct curettes medially, and drill uncovertebral spurs with a 3 mm diamond burr at a 45 degree medial trajectory. If injured, apply direct pressure with a cottonoid, pack with haemostatic agents, maintain MAP greater than 80 mmHg, avoid blind bipolar or clipping (posterior circulation stroke), and obtain postoperative angiography.
Incomplete posterior decompression is the commonest cause of persistent radiculopathy after ACDF. Pass a ball probe circumferentially to confirm the posterior annulus is cleared; for myelopathy, resect the PLL until dural pulsations return; for radiculopathy, foraminotomise until you can "see blue sky" epidural veins around the freed nerve.
The right recurrent laryngeal nerve loops under the subclavian artery and ascends obliquely in the tracheoesophageal groove, making it more vulnerable to a retractor (5-8 percent injury versus 1-2 percent on the left, where it loops predictably under the aortic arch). Use a left approach unless the surgeon is left-handed or there is prior left-neck surgery, and deflate the endotracheal cuff every 30 minutes to relieve nerve compression.
Aftercare & Complications
Recovery | Phase | Timing | Immobilisation | Activity and imaging | |-------|--------|----------------|----------------------| | 1 | 0-24 hours | Soft collar for comfort; head of bed 30 degrees | Airway monitoring in PACU; clear liquids to soft diet; drain out on POD1 | | 2 | 1-6 weeks | Collar weaned over 2 weeks (comfort only) | Immediate mobilisation; no lifting greater than 10 pounds; AP and lateral radiographs at 2 weeks | | 3 | 6 weeks to 3 months | Collar for heavy tasks only | Desk work at 2-4 weeks; flexion-extension radiographs at 3 months | | 4 | 3-12 months | None | CT at 6-12 months if pseudarthrosis suspected; manual labour at 3-4 months; heavy lifting once fusion confirmed | Overall clinical success (Odom excellent or good) is 85-90 percent for radiculopathy and 70-80 percent for myelopathy, with return to work around 75-80 percent at 6 months for radiculopathy. VTE: a low-risk operation - early mobilisation suffices; high-risk patients (BMI greater than 35, prior VTE, cancer, surgery greater than 3 hours) add sequential compression devices and LMWH from POD1 (avoid preoperative dosing - haematoma risk). Pain: multimodal - paracetamol, gabapentin for radicular pain, a short opioid course; avoid NSAIDs in the first 3 months (weak theoretical fusion concern). Complications
- Recognition
- Pulsatile arterial bleeding from the lateral disc space; possible occult retropharyngeal loss; hypotension if blood loss greater than 500 mL
- Prevention
- Limit lateral dissection to the medial border of the uncinate; preoperative CTA for revision; 3 mm diamond burr at 45 degrees medial trajectory
- Management
- Direct pressure with cottonoid; pack with haemostatic agents; avoid blind bipolar (stroke); maintain MAP greater than 80 mmHg; postoperative angiography; vascular consult
- Recognition
- Postoperative hoarseness, weak cough, aspiration; laryngoscopy shows vocal cord paralysis (right 5-8%, left 1-2%)
- Prevention
- Left-sided approach; no retraction in the tracheoesophageal groove; deflate or reposition the ET cuff every 30 minutes; limit operative time
- Management
- Mostly transient (resolve by 6-12 months); speech therapy, thickened liquids, head-turn; medialisation thyroplasty if persistent at 12 months; bilateral palsy needs an emergency airway
- Recognition
- Intraoperative mucosa or NG tube visible; postoperative fever, neck swelling, subcutaneous emphysema, dysphagia; Gastrografin swallow shows extravasation
- Prevention
- Gentle medial retraction with smooth (not toothed) blades; palpate the NG tube first; bipolar only near midline; intermittent ET-cuff deflation
- Management
- Intraoperative: primary repair in two layers plus an SCM flap, NGT decompression 7-10 days, antibiotics. Delayed (48-96 h): NPO, IV antibiotics; large tears need exploration and repair; untreated mortality 10-20 percent
- Recognition
- Deltoid and biceps weakness 24-72 hours postoperatively; shoulder abduction less than 45 degrees; usually no sensory deficit
- Prevention
- Avoid over-distraction (limit to 2 mm); gradual distraction; do not oversize the graft; decompress C4-5 foramen before distracting
- Management
- Most recover spontaneously (80-90 percent at 1 year); physiotherapy, shoulder subluxation bracing; EMG at 6 weeks; persistent at 2 years - tendon transfers
- Recognition
- Intraoperative SSEP or MEP signal loss; postoperative quadriparesis, sensory level, bladder dysfunction
- Prevention
- Appropriate graft sizing; trial spacer before the final implant; no retractor blades in the disc; neuromonitoring for stenosis or OPLL
- Management
- Remove compressive graft or hardware; emergent MRI; return to OR if compression persists; high-dose methylprednisolone is controversial; DVT prophylaxis and bowel or bladder care
- Recognition
- Neck swelling, respiratory distress, dysphagia within the first 6 hours (90 percent within 24 hours); stridor; drain output greater than 100 mL/hour
- Prevention
- Meticulous haemostasis before closure; bipolar the epidural and vertebral-body veins; reverse anticoagulation; normotensive emergence
- Management
- Airway first; if compromised, open the wound at the bedside (remove skin sutures, evacuate clot), secure the airway, then return to OR for washout and haemostasis
- Recognition
- Difficulty swallowing solids or liquids; peaks at 1-2 weeks, improves by 3 months; modified barium swallow shows pharyngeal dysfunction
- Prevention
- Minimise retraction pressure and duration; zero-profile implants (about 50 percent reduction); smooth low-profile plates; limit operative time
- Management
- Speech therapy, modified diet (thickened liquids), head-turn, NSAIDs; most resolve by 6 months; evaluate for graft extrusion or plate prominence if persistent
Late complications Pseudarthrosis (non-union) occurs in about 3-7 percent of single-level, 12-18 percent of two-level, and 30-40 percent of three-level un-instrumented fusions; anterior plating halves these rates. Risk factors are smoking (2.7x), multilevel fusion, allograft, inadequate endplate preparation, NSAIDs and diabetes. Recognise it with persistent neck pain or recurrent radiculopathy and greater than 2 mm motion on flexion-extension radiographs or no bridging bone on CT. Manage asymptomatic pseudarthrosis expectantly (25 percent eventually fuse); revise a symptomatic non-union with autograft, anterior plating, or posterior lateral-mass fusion for multilevel anterior failure. Adjacent-segment disease occurs at about 2.9 percent per year (25.6 percent cumulative at 10 years) from biomechanical stress transfer, highest at C5-6 and C6-7. Maintain or restore cervical lordosis to reduce risk; treat progressive disease as primary cervical pathology (ACDF or arthroplasty at the adjacent level).
Viva & Exam Focus
POETSACDF approach layers - 'POETS'
DUBSACDF decompression sequence - 'DUBS'
- Location
- Tracheoesophageal groove; the right side is more vulnerable (loops under the subclavian and ascends obliquely)
- How to protect it
- Left-sided approach; no retractor in the groove; deflate or reposition the ET cuff every 30 minutes; neuromonitoring for revision or multilevel
- Location
- Exits the vagus at C3 and pierces the thyrohyoid membrane; at risk in high C3-4 or C2-3 approaches
- How to protect it
- Dissect only to the level required; gentle superior handheld retraction; avoid monopolar above C4
- Location
- Enters the C6 transverse foramen (90 percent), 3 mm lateral to the uncinate; anomalous course in 5 percent
- How to protect it
- Limit lateral dissection to the medial border of the uncinate; preoperative CTA for revision; angled curettes directed medially; 3 mm diamond burr at 45 degrees
- Location
- Canal AP diameter about 14 mm with the cord occupying 12 mm - a minimal safety margin in stenosis
- How to protect it
- Decompress lateral-to-medial; upbiting Kerrison only; trial spacer before the final implant; SSEP or MEP for stenosis or OPLL
- Location
- Immediately medial to the plane; a 3 mm wall vulnerable to retractor pressure and diathermy
- How to protect it
- Smooth (not toothed) medial blade; palpate the NG tube first; intermittent ET-cuff deflation; bipolar only near the midline
Clinical Decision Scenarios
Practise clinical reasoning and management decisions out loud
“A 52-year-old lawyer presents with 8 months of right arm pain radiating to the thumb and index finger, with numbness. MRI shows a right C6-7 paracentral disc herniation compressing the C7 nerve root. He has failed 3 months of physiotherapy and anti-inflammatories. How would you manage this patient and what are the key operative steps if you proceed with ACDF?”
“During ACDF at C5-6, after anterior discectomy you are performing posterior decompression with a Kerrison rongeur when you encounter brisk arterial bleeding from the left lateral disc space. What has happened, what are your immediate steps, and how do you prevent this complication?”
“You are planning ACDF for a 45-year-old manual labourer with C5-6 and C6-7 disc herniations causing bilateral arm pain. What are your graft options and how would you counsel the patient regarding fusion rates, complications, and expected functional outcomes for two-level ACDF?”
Indications
- Radiculopathy with concordant MRI compression failing 6-12 weeks of conservative care
- Progressive myelopathy with cord compression (modified JOA decline)
- Post-traumatic instability, cervical kyphotic deformity, anterior tumour or infection needing corpectomy
- Contraindications: active infection, severe osteoporosis (T-score less than -3.5), medical instability
Anatomy and exposure
- Carotid sheath (lateral: carotid, jugular, vagus) retracted laterally; visceral column (trachea, esophagus, thyroid) retracted medially
- Recurrent laryngeal nerve in the tracheoesophageal groove (not seen) - right 5-8 percent, left 1-2 percent
- Vertebral artery enters the C6 transverse foramen, 3 mm lateral to the uncinate
- Longus colli (elevated 1.5 cm bilaterally) defines the safe lateral limit
- Surface landmarks: C3-4 thyroid, C4-5 cricoid, C5-6 omohyoid or carotid tubercle, C6-7 two fingerbreadths above the suprasternal notch
Critical steps
- Left-sided approach; blunt finger dissection in the avascular plane between carotid sheath and visceral column
- Intraoperative lateral fluoroscopy with a spinal needle to confirm the level - wrong-level surgery is a never event
- Complete discectomy to the posterior annulus; curette endplates to bleeding bone
- Posterior decompression: upbiting Kerrison for osteophytes, 3 mm diamond burr at 45 degrees medial for the uncinate
- Graft 1 mm larger than posterior disc height, restoring 4-6 degrees lordosis; plate mandatory for 2 or more levels, within 5 mm of the disc, screws angled 12-15 degrees away from the adjacent disc
Danger zones
- Recurrent laryngeal nerve - left approach, deflate the ET cuff every 30 minutes
- Vertebral artery - stay medial to the uncinate, preoperative CTA for revision, direct pressure if injured
- Spinal cord - upbiting Kerrison only, trial spacer first, neuromonitoring for stenosis
- Esophagus - smooth medial blade, palpate the NG tube, bipolar only
- Superior laryngeal nerve - at risk in high C3-4 approaches, gentle superior retraction
Graft and plate
- Autograft: 98 percent fusion, 20 percent donor pain
- Allograft: 95 percent with plating, no donor morbidity
- PEEK cage: 92-95 percent, radiolucent, 5-8 percent subsidence
- Two-level plate reduces pseudarthrosis from 18 to 8 percent (Wang); zero-profile devices halve early dysphagia
Complications and outcomes
- RLN palsy 1-8 percent; mostly transient, medialisation if persistent at 12 months
- Dysphagia 30-70 percent early, 10-20 percent at 1 year; C5 palsy 4-7 percent; vertebral artery injury 0.3-0.5 percent
- Postoperative haematoma 0.5-2 percent - airway emergency, open the wound at the bedside
- Pseudarthrosis: single 3-7 percent, two-level 12-18 percent; ASD 2.9 percent per year (25 percent at 10 years)
- Fusion rates with plating: single 95-98 percent, two-level 90-95 percent, three-level 85-90 percent
Postoperative care
- Airway monitoring in PACU 4-6 hours; haematoma peaks within the first 24 hours
- Soft collar for comfort only (not structural); weaned over 2 weeks; immediate mobilisation
- Radiographs at 2 weeks, flexion-extension at 3 months, CT at 6-12 months if pseudarthrosis suspected
- Return to work: desk 2-4 weeks, manual 3-4 months; VTE prophylaxis only if high-risk
Background & Evidence
Epidemiology and pathoanatomy. Degenerative cervical disease is driven by disc desiccation, annular attenuation and osteophyte formation, with the greatest mechanical stress - and therefore the highest operative frequency - at C5-6 (about 60 percent) and C6-7 (about 25 percent). Ossification of the posterior longitudinal ligament contributes disproportionately in Asian populations (about 40 percent show some OPLL on CT) and converts a soft disc problem into a circumferential cord-compression problem. The result is radiculopathy (foraminal stenosis from uncovertebral and facet osteophytes) or myelopathy (cord compression with possible T2 signal change). Outcomes by construct
- Fusion at 1 year
- 95-98 percent
- Clinical success
- 85-90 percent excellent or good (radiculopathy)
- Notes
- Plating may be omitted in selected soft-disc disease
- Fusion at 1 year
- 90-95 percent
- Clinical success
- 80-90 percent
- Notes
- Plate mandatory - pseudarthrosis falls from about 18 to 8 percent (Wang)
- Fusion at 1 year
- 85-90 percent
- Clinical success
- 70-80 percent (myelopathy)
- Notes
- Anterior instrumentation recommended; consider supplementary posterior fixation
- Fusion
- about 98 percent
- Advantages
- Gold-standard biologics, no disease-transmission risk
- Caveats
- 20 percent donor-site pain; added operative time
- Fusion
- about 95 percent (with plate)
- Advantages
- No donor morbidity
- Caveats
- 8-12 percent subsidence
- Fusion
- 92-95 percent
- Advantages
- Radiolucent, low-profile
- Caveats
- 5-8 percent subsidence
- Fusion
- about 98 percent
- Advantages
- High fusion in revision pseudarthrosis
- Caveats
- About 2x dysphagia, 18 percent heterotopic ossification
Plate versus no plate. Single-level ACDF in soft-disc disease with good endplate contact can be performed without a plate (or with a stand-alone or zero-profile cage). For two or more levels an anterior plate is standard - Wang et al. reduced two-level pseudarthrosis from 25 percent (un-plated) to 0 percent (plated) and preserved lordosis. Long anterior constructs (three-level and corpectomy reconstructions) warrant anterior instrumentation and, where un-plated non-union rates are high, consideration of supplementary posterior fixation. Arthroplasty versus fusion (FDA IDE trials). Cervical total disc replacement (Bryan, Prestige LP, ProDisc-C, Mobi-C, Secure-C) is non-inferior to ACDF for single-level disease across NDI, VAS and neurological success out to 5-10 years. For two-level disease (Mobi-C, 7-year RCT), TDR was clinically superior in composite success (60.8 percent versus 34.2 percent) with lower index-level reoperation (4.4 percent versus 16.2 percent) and lower adjacent-level reoperation (4.4 percent versus 11.3 percent); single-level adjacent-level reoperation was 3.7 percent TDR versus 13.6 percent ACDF. Limitations are higher implant cost, technical demands, and firm contraindications (significant facet arthrosis, OPLL, instability, marked osteoporosis) - ACDF remains the default where these are present. Key evidence base. The anterior cervical approach and tricortical interbody fusion were described by Smith and Robinson in 1958 (historical, pre-PubMed). Bohlman's 122-patient autograft series (1993) established the benchmark for un-plated ACDF - pseudarthrosis in 24 of 195 segments, higher with multilevel fusion, with near-complete neurological recovery. Hilibrand and colleagues (1999) defined adjacent-segment disease at 2.9 percent per year (25.6 percent cumulative at 10 years), highest at C5-6 and C6-7. Wang et al. (2000) showed two-level plating eliminated pseudarthrosis and preserved lordosis. Riley et al. (2005) found new dysphagia in 30 percent at 3 months, scaling with the number of levels operated. Fountas et al. (2007), in a 1015-patient series, set complication benchmarks (overall morbidity 19.3 percent, isolated dysphagia 9.5 percent, haematoma 5.6 percent, symptomatic RLN palsy 3.1 percent, esophageal perforation 0.3 percent). Yue et al. (2005) confirmed allograft-plus-plate durability at 5-11 years. The FDA IDE trials (Radcliff, Mobi-C, 2017) defined the modern arthroplasty-versus-fusion evidence base. The verified studies below carry full PubMed verification. Guidelines, registries and global practice Guidance across societies is broadly concordant:
- NASS / AAOS (US): ACDF supported for radiculopathy or myelopathy with concordant imaging refractory to non-operative care; single-level total disc replacement endorsed as an alternative in appropriately selected patients.
- NICE / BOA (UK): surgery reserved for progressive myelopathy or radiculopathy failing conservative management; emphasis on shared decision-making and avoidance of fusion for isolated axial neck pain.
- AOSpine (global): standardised classification and decision frameworks for degenerative cervical myelopathy; early surgery favoured for moderate-to-severe or progressive myelopathy. Across all frameworks, isolated axial neck pain without neural compression or instability is a weak or controversial indication for fusion. Registry and large-cohort signals are consistent worldwide: adjacent-segment disease at about 2.9 percent per year (Hilibrand), highest at C5-6 and C6-7; dysphagia the commonest early morbidity scaling with construct length (Riley); and lower index- and adjacent-level reoperation with TDR versus ACDF at 7 years in level-1 trials, most pronounced for two-level disease (Mobi-C).
References
Robinson ACDF for cervical radiculopathy - long-term follow-up of 122 patients
- 122 patients treated by Robinson anterior discectomy and arthrodesis with autogenous iliac-crest graft (no plating), mean 6-year follow-up
- Pseudarthrosis at 24 of 195 operated segments; risk significantly higher after multilevel than single-level arthrodesis (p less than 0.01)
- 53 of 55 patients with a motor deficit recovered completely; 71 of 77 with sensory loss regained sensation; no patient had increased postoperative deficit
Increased fusion rates with cervical plating for two-level ACDF
- Retrospective comparison of 60 two-level ACDFs by a single surgeon (32 plated, 28 un-plated), mean 2.7-year follow-up
- Pseudarthrosis 0% with plating versus 25% without plating (p=0.003)
- Mean segmental kyphosis 0.4 degrees with plating versus 4.9 degrees in un-plated non-unions (p=0.0001), with less graft collapse
Long-term ACDF with allograft and plating: 5- to 11-year follow-up
- 71 patients reviewed at mean 7.2 years after ACDF with structural allograft and anterior plate
- Fusion in 92.6% of disc spaces, symptom resolution greater than 82%, with no graft extrusion or migration
- Radiographic adjacent-level degeneration in 73.2%, but further cervical surgery required in only 19.7% (mostly for adjacent-level disease)
Dysphagia after ACDF: prevalence and risk factors (multicentre cohort)
- 454 patients across 23 sites; new dysphagia reported by 30% at 3 months, persisting in 21.3% at 24 months
- Risk rose with the number of operated levels at 3 months: 1 level 19.8%, 2 levels 33.3%, 3 or more levels 39.1%
- Duration of pre-existing pain and number of levels predicted dysphagia; affected patients had worse disability and physical health scores
Cervical disc arthroplasty (Mobi-C) versus ACDF: RCT with 7-year follow-up
- Prospective randomised FDA IDE trial; 599 patients (one- and two-level disease), 80.2% follow-up at 7 years
- Two-level composite success: TDR 60.8% versus ACDF 34.2% (p less than 0.0001); single-level non-inferior (55.2% vs 50%)
- Lower secondary surgery with TDR: single-level adjacent-level reoperation 3.7% vs 13.6% (p=0.007); two-level index-level reoperation 4.4% vs 16.2% (p=0.001)