Cervical Fusion (ACDF): Causes, Symptoms, Diagnosis and Treatment — Overview, Diagnosis & Treatment Options | MyMedicPlus

Anterior cervical discectomy and fusion (ACDF) is one of the most commonly performed spinal operations globally, addressing degenerative cervical disease causing nerve root compression (radiculopathy) or spinal cord compression (myelopathy). The procedure involves a small anterior neck incision to remove the damaged intervertebral disc and decompress the neural structures, followed by fusion of the adjacent vertebral bodies using an interbody spacer (allograft bone or polyetheretherketone [PEEK] cage) secured with a titanium plate. ACDF can be performed at one to four levels and is increasingly performed as day surgery or short-stay procedure for single-level pathology. An alternative motion-preserving procedure — cervical disc arthroplasty (total disc replacement) — is available for selected patients with single- or two-level disease to preserve segmental motion and potentially reduce adjacent segment disease. Outcomes are excellent: over 90% of appropriately selected patients achieve significant improvement in arm pain and neurological function.

Cervical disc herniation is the most common indication for ACDF, caused by rupture or bulging of the nucleus pulposus posterolaterally to compress a cervical nerve root. Cervical spondylosis — degenerative disc disease with osteophyte (bone spur) formation narrowing the neuroforamina or central spinal canal — causes radiculopathy and myelopathy, particularly at C5-6 and C6-7 levels. Degenerative disc disease risk factors include age over 40, genetic predisposition to disc degeneration, prior repetitive axial cervical loading (occupational or sporting), smoking (impairs disc nutrition through reduced blood supply), obesity, and male sex. Traumatic disc herniation follows hyperflexion or hyperextension injuries. Cervical instability requiring fusion may result from rheumatoid arthritis (atlantoaxial subluxation), trauma, or iatrogenic destabilization. Failed non-surgical management (physiotherapy, NSAIDs, selective nerve root injections for 6-12 weeks) is required before elective ACDF.

Cervical radiculopathy: sharp, shooting arm pain (brachialgia) radiating in a dermatomal distribution from the neck into the shoulder, arm, forearm, or fingers; numbness and paresthesia in the same distribution; and weakness of specific muscle groups (C5: deltoid and biceps; C6: wrist extensors; C7: triceps; C8: finger flexors). Neck pain and reduced cervical range of motion may accompany arm symptoms but are not by themselves indications for surgery. Cervical myelopathy (spinal cord compression) is the more urgent indication: progressive gait instability with a wide-based or shuffling gait, loss of hand fine motor skills (difficulty with buttons, writing, using cutlery), and bladder urgency or incontinence. A positive Lhermitte sign (electric shock sensation radiating down the spine on neck flexion) indicates cord compression.

MRI of the cervical spine with and without gadolinium is the primary diagnostic tool: it identifies the level and extent of disc herniation or spondylotic cord compression, assesses T2 signal change within the spinal cord (myelomalacia — intrinsic cord signal indicates established cord damage and more urgent surgical indication), and evaluates foraminal stenosis at each level. CT myelogram provides complementary anatomical detail for surgical planning, particularly in patients with MRI contraindications. Plain cervical radiographs with flexion-extension views assess alignment and dynamic instability. Nerve conduction studies and electromyography (NCS/EMG) localize the affected nerve root level and exclude peripheral nerve entrapment (carpal tunnel syndrome, cubital tunnel syndrome). Modified Japanese Orthopaedic Association (mJOA) score quantifies myelopathy severity and guides urgency of surgical intervention.

Conservative management as first-line: 6-12 weeks of physiotherapy, anti-inflammatory medication (NSAIDs), cervical collar for immobilization, and selective nerve root block with corticosteroids for radiculopathy. Surgery (ACDF) is indicated for: failure of conservative therapy for radiculopathy; progressive or severe neurological deficit; and cervical myelopathy (which may warrant earlier surgery to prevent irreversible cord damage). ACDF procedure: general anesthesia, anterior approach through a skin crease incision, discectomy and decompression under intraoperative fluoroscopy, implantation of autograft, allograft, or PEEK cage packed with bone graft, and fixation with a locking titanium plate. Total disc arthroplasty (TDR) for single- or two-level pathology in younger patients: preserves motion, potentially reduces adjacent segment disease risk. Posterior cervical laminoplasty or laminectomy and fusion is an alternative for multi-level spondylotic myelopathy.

Prognosis after anterior cervical discectomy and fusion (ACDF) is excellent for appropriately selected patients. For cervical radiculopathy, over 90-95% of patients experience significant improvement in arm pain and neurological function within 6 weeks of surgery, with complete or near-complete resolution in most cases. Neurological recovery (motor strength and sensory function) may continue for up to 12-18 months as nerve regeneration progresses. For cervical spondylotic myelopathy, the prognosis is more variable: most patients achieve stabilization or modest improvement in myelopathy (modified JOA score improvement of 1-2 points is typical), but recovery is less predictable the longer cord compression has been present or the more severe the baseline deficit — patients operated within 12-24 months of myelopathy onset have substantially better outcomes than those with long-standing cord dysfunction. Radiographic fusion is confirmed in 90-95% of single-level and 80-90% of multi-level ACDF within 12 months. Pseudarthrosis (failed fusion) occurs in approximately 2-5% of cases and may require revision surgery. Adjacent segment disease requiring reoperation occurs in approximately 3% of patients per year; by 10 years, approximately 20-25% of ACDF patients require surgery at an adjacent level. Cervical disc arthroplasty may reduce adjacent segment reoperation rates compared to fusion in appropriately selected single-level patients. Key prognostic factors include severity and duration of pre-operative neurological deficit, intrinsic spinal cord T2 signal (myelomalacia on MRI — indicates established cord injury), age, number of levels fused, and patient compliance with post-operative rehabilitation. Clinical follow-up at 6 weeks, 3 months, 6 months, and 1 year post-operatively is standard, with imaging if symptoms recur or persist.

Primary prevention of cervical disc degeneration: ergonomic workstation setup with monitor at eye level, proper lifting technique that avoids repetitive cervical axial loading, core and cervical muscle strengthening exercises, avoiding prolonged smartphone or device use in a flexed-neck posture (text neck), maintaining healthy body weight, and smoking cessation (smokers have a 3-fold increased risk of symptomatic disc degeneration). For sports participants: wearing appropriate protective equipment in contact sports, proper technique training to minimize cervical injury risk, and prompt evaluation of any cervical spine injury before return to sport. Workplace ergonomics assessment for individuals with desk-based jobs can significantly reduce cervical spine strain. Patients with previous cervical disc disease should receive structured rehabilitation including neck muscle strengthening to reduce risk of adjacent level degeneration and recurrent disc herniation.

Seek urgent neurosurgical or spine specialist evaluation for: any signs of cervical myelopathy — gait instability, hand weakness or loss of fine motor skills, or bladder/bowel dysfunction — as delayed treatment risks permanent cord injury; progressive neurological deficit in the arm (worsening weakness or numbness); arm pain or numbness not improving after 4-6 weeks of conservative management. Routine orthopaedic or neurosurgical referral is appropriate for: persistent neck pain with arm radiation that interferes with daily activities; positive Spurling's test (reproduction of arm symptoms with neck extension and lateral flexion toward the affected side); and a first episode of severe radiculopathy not responding to analgesics. MRI cervical spine should be ordered by the primary care physician before referral where possible to facilitate an efficient specialist consultation.