Summary Cervical radiculopathy is characterized by unilateral arm pain, numbness and tingling in a dermatomal distribution in the upper extremity, and weakness in specific muscle groups Evaluation consists of a thorough neurologic examination, cervical spine radiographs (including flexion-extension views), and MRI of the cervical spine Nonoperative treatment is successful in 75-90% of patients. Surgical decompression is reserved for refractory cases or patients with progressive neurologic deficits Epidemiology Incidence 107.3 per 100,000 men annually 63.5 per 100,000 women annually peaks in 50-54 y/o Risk factors white race cigarette smoking prior lumbar radiculopathy Etiology Pathophysiology causes degenerative cervical spondylosis discosteophyte complex and loss of disc height chondro-osseous spurs of the facet and uncovertebral joints disc herniation ("soft disc") intraforaminal radicular pain predominantly posterolateral most common located between posterior edge of uncinate and lateral edge of PLL mostly motor symptoms midline herniation usually presents with myelopathic symptoms double-crush phenomenon combined cervical root and distal nerve compression decreased axoplasmic flow from root compression predisposes downstream nerves to peripheral entrapment syndromes rare causes intraspinal/extraspinal tumors trauma with nerve root avulsion synovial cysts meningeal cysts dural arteriovenous fistulae tortuous vertebral arteries neural compression nerve root irritation caused by direct compression irritation by chemical pain mediators, including: IL-1 IL-6 substance P neuropeptide Y calcitonin gene-related peptide bradykinin TNF-⍺ prostaglandins affects the nerve root below C6-7 disease will affect the C7 nerve root Anatomy Articulations facet joints facet hypertrophy and osteophytes can impinge on the nerve root posteriorly disc space loss of disc height can decrease the volume of neuroforamen uncovertebral joints osteophytes from posterior joint can impinge on exiting nerve anteriorly Intervertebral disc annulus fibrosus thick fibrous outer layer of the intervertebral disc contains type I collagen thicker ventrally than dorsally nucleus pulposus "cushioning" between the vertebral bodies contains type II collagen and glycosaminoglycans (GAGs) GAGs are highly negatively charged and attract large amounts of water molecules GAGs break down with increasing age 90% water content in patients <30 y/o decreases to 70% by eighth decade of life Nerve root anatomy key differences between cervical and lumbar spine pedicle/nerve root mismatch cervical spine C6 nerve root travels above C6 pedicle (mismatch) lumbar spine L5 nerve root travels under L5 pedicle (match) extra C8 nerve root (no C8 pedicle) allows transition horizontal (cervical) vs. vertical (lumbar) anatomy of nerve root because of the vertical anatomy of a lumbar nerve root, a paracentral and foraminal disc will affect different nerve roots because of horizontal anatomy of a cervical nerve root, a central and foraminal disc will affect the same nerve root ventrolateral course from spinal cord predisposes to ventral compression Presentation Symptoms occipital headache (common) trapezial or interscapular pain neck pain may present with an insidious onset of neck pain that is worse with vertebral motion origin may be discogenic or mechanical due to facet arthrosis pain may radiate to shoulders unilateral arm pain aching pain radiating down the arm often global and nondermatomal unilateral dermatomal numbness & tingling numbness/tingling in thumb (C6) numbness/tingling in middle finger (C7) unilateral weakness difficulty with overhead activities (C7) decreased grip strength (C7) Physical exam common and testable exam findings C4 radiculopathy scapular winging numbness and pain at the base of the neck C5 radiculopathy deltoid and biceps weakness diminished biceps reflex pain and numbness in the superior shoulder and lateral upper arm C6 radiculopathy brachioradialis and wrist extension weakness diminished brachioradialis reflex paresthesias in the thumb and radial arm C7 radiculopathy triceps and wrist flexion weakness diminished triceps reflex paresthesia in the middle finger most commonly affected nerve root in several studies C8 radiculopathy weakness to distal phalanx flexion of middle and index finger (difficulty with fine motor function) paresthesias in ring and little finger C8 radiculopathy is extremely rare and often manifests similarly to ulnar neuropathy T1 radiculopathy intrinsic hand muscle weakness axillary numbness ipsilateral Horner's syndrome provocative tests Spurling's test simultaneous extension, rotation to affected side, lateral bend, and vertical compression reproduces symptoms in ipsilateral arm narrowing of the intervertebral foramina causes exacerbation of symptoms specific, but not sensitive for radiculopathy shoulder abduction test shoulder abduction relieves symptoms shoulder abduction (lifting arm above head) often relieves symptoms decreases tension on affected nerves valuable physical exam test to differentiate cervical pathology from other causes of shoulder/arm pain upper limb tension tests valsalva maneuver neck distraction test myelopathy check for findings of myelopathy in large central disc herniations Imaging Radiographs recommended views AP, lateral, and oblique views of cervical spine obtain flexion and extension views if suspicion for instability findings general degenerative changes of uncovertebral and facet joints osteophyte formation disc space narrowing & endplate sclerosis lateral radiograph sagittal alignment and spinal canal diameter oblique radiograph best view to identify foraminal stenosis caused by osteophytes flexion and extension views angular or translational instability look for compensatory subluxation above or below the spondylotic/stiff segment sensitivity & specificity changes often do not correlate with symptoms 70% of patients by 70 y/o will have degenerative changes seen on plain x-rays MRI indications red flags: fever weight loss pain that wakes the patient up at night persistent symptoms despite 6 weeks of conservative treatment motor weakness views T2 axial imaging gives needed information on the status of the soft tissues CSF appears hyperintense loss of CSF signal around the cord and nerve roots findings disc degeneration and herniation foraminal stenosis with nerve root compression (loss of perineural fat) central compression with CSF effacement sensitivity & specificity high rate of false positives (28% >40 y/o will have findings of HNP or foraminal stenosis) >50% >40 y/o will have a degenerated disc CT indications preoperative gives useful information on bony anatomy, including osteophyte formation, that could be compressing the neural elements planning instrumentation detect ossification of the posterior longitudinal ligament may not be as evident on MRI or radiography postoperative study of choice to evaluate for postoperative pseudarthrosis CT myelography indications largely replaced by MRI useful in patients who cannot have an MRI (e.g. pacemaker) useful in patients with prior surgery and hardware causing artifact on MRI technique intrathecal injection of water soluble contrast given via C1-2 puncture and allowed to diffuse caudally lumbar puncture and allowed to diffuse proximally by putting patient in Trendelenburg position Discography indications controversial and rarely indicated in cervical spondylosis techniques approach is similar to that used with ACDF risks include esophageal puncture and disc infection Studies Nerve conduction studies high false negative rate sensitivity 40-70% not a good screening study may be useful to distinguish a peripheral from central process (e.g. ALS) fibrillations and positive sharp waves in the affected distribution may not manifest until 3 weeks after the onset of symptoms paraspinal muscles are affected before appendicular muscles sensory nerve action potentials are typically normal compression is usually proximal to the dorsal root ganglion compound muscle action potential proportionally decreases to muscle atrophy Selective nerve root corticosteroid injections may help confirm level of radiculopathy in patients with multilevel disease and when physical exam findings and EMG fail to localize level Differential Carpal tunnel syndrome Cubital tunnel syndrome Parsonage-Turner syndrome Thoracic outlet syndrome Cervical myelopathy Brachial plexus injury Treatment Nonoperative rest, medications, and rehabilitation indications 75% of patients with radiculopathy improve with nonoperative management improvement with resorption of soft discs and decreased inflammation around irritated nerve roots return to play indicated after resolution of symptoms and repeat MRI demonstrating no cord compression studies have shown return to play expedited with brief course of oral methylprednisolone no increased risk of subsequent spinal cord injury selective nerve root corticosteroid injections indications may be considered as therapeutic or diagnostic option outcomes provides long-term relief in 40-70% of cases increased risk when compared to lumbar selective nerve root injections with the following rare complications: dural puncture meningitis epidural abscess nerve root injury Operative anterior cervical discectomy and fusion indications persistent and disabling pain after failing three months of conservative management progressive and significant neurologic deficits static neurologic deficit associated with significant radicular pain outcomes remains gold standard in surgical treatment of cervical radiculopathy single level ACDF is not a contraindication for return to play for athletes very high success rate with single level disease higher rate of pseudarthrosis with multilevel procedures 20% for single level ACDF vs. >50% for multilevel ACDF pseudarthrosis rate does not appear to correlate with clinical outcomes anterior cervical foraminotomy indications isolated unilateral nerve root compression avoidance of fusion high risk patients for pseudarthrosis smokers diabetics outcomes limited studies not widely accepted 98% excellent outcomes reported in literature posterior foraminotomy indications foraminal soft disc herniation causing single level radiculopathy may be used for osteophytic foraminal narrowing failed nonoperative treatment high risk patients with anterior approach previous anterior surgery abnormal anatomy contraindications large central disc herniation cervical myelopathy instability OPLL kyphotic deformity outcomes >91% success rate reduces the risk of iatrogenic injury that can occur with anterior approach low complication rate (~3%) no difference in outcomes compared to ACDF faster return to work and lower treatment cost than ACDF cervical disc arthroplasty (CDA) indications (controversial) single level disease with minimal facet arthrosis outcomes studies show equivalence to ACDF no difference in arm pain, NDI, SF-36 scores, or neurologic improvement effect on adjacent segment disease (ASD) remains unclear some studies show 3% per year for all approaches systematic reviews have demonstrated no difference in ASD rate between CDA and ACDF lower neck pain intensity and frequency with CDA high incidence of heterotopic bone formation 60% of cases no effect on motion profile Techniques Rest, medications, and rehabilitation techniques (very few substantiated by evidence) immobilization immobilization for short period of time (<1-2 weeks) may help by decreasing inflammation and muscle spasms prolonged immobilization should be avoided cervical muscle atrophy medications NSAIDs / COX-2 inhibitors oral corticosteroids GABA inhibitors (gabapentin) narcotics short-term use in the acute phase muscle relaxants rehabilitation moist heat cervical isometric exercises traction/manipulation avoid in myelopathic patients Selective nerve root corticosteroid injections approach fluoroscopic guidance injection consisting of steroid and local anesthetic studies have shown no difference in long-term pain relief with local anesthetic and combined steroid and local anesthetic alone Anterior cervical discectomy and fusion (ACDF) approach uses Smith-Robinson anterior approach transverse incision for 1- and 2-level disease longitudinal incision for multilevel disease and corpectomies or patients with short and thick necks C7-T1 exposure increased risk of thoracic duct injury with left-sided approach lower risk of recurrent laryngeal nerve injury with left-sided approach recurrent laryngeal nerve passes between trachea and esophagus retractor displacement compresses nerve against inflated endotracheal tube cuff deflation can theoretically decrease recurrent laryngeal nerve injury superficial landmarks for levels C1-2: Inferior margin of the mandible C3-4: Hyoid C4-6: Thyroid cartilage C5-6: Cricoid cartilage techniques decompression placement of bone graft increases disc height and indirectly decompresses the neural foramen corpectomy and strut graft may be required for multilevel spondylosis fixation anterior plating functions to increase fusion rates and preserve position of interbody cage or strut graft increased cost and complication risk for increased exposure decreased rates of implant extrusion and graft collapse historically, plating required bicortical fixation (Caspar plates) high risk for neurologic injury intraoperative fluoroscopy used to prevent over penetration of screws modern plating utilizes a constraining mechanism to allow sufficient fixation with unicortical screws dynamic plates allow controlled settling of the interbody construct and physiologic loading of the graft theoretical benefit of increased fusion rates and decreased screw pull out static plates maintain screws at fixed angles through plate (similar to locking plate) in single-level disease, no difference in fusion rates with or without plating in multilevel disease, increased fusion rate, decreased graft complications, lower reoperation rate, and earlier return to work with plating graft autograft locally harvested iliac crest bone graft gold standard donor site pain minimized with limited surgical exposure careful dissection of the inner and outer tables of the ilium allograft higher potential for disease transmission higher pseudarthrosis rates (41% vs. 27%) higher graft subsidence rates (28% vs. 16%) structural graft iliac crest fibular strut patella postoperative care ambulatory the day of surgery soft collar immobilization for short period of time prolonged immobilization in hard collar if anterior plating not used range of motion and strengthening beginning at 6 weeks return to full activity by 3 months pros and cons complications of anterior surgery, including persistent swallowing problems adjacent segment disease adjacent-level ossification development more likely to occur if the anterior cervical plate is placed <5 mm from the superior adjacent disc space Anterior cervical foraminotomy approach anterolateral approach to the cervical spine longus coli split longitudinally medial to the anterior tubercle of the transverse process technique removal of uncovertebral joint decompression of the exiting nerve root pros and cons avoids fusing the involved level potential risk of sympathetic chain and vertebral artery injury Posterior foraminotomy approach positioning sitting comfortable position limits epidural bleeding (less engorgement of veins compared to prone positioning) risk of venous air embolism prone familiar approach for most surgeons posterior approach open muscle stripping from lamina and spinous process lateral exposure to the lateral border of the lateral mass microendoscopic minimally invasive approach reduced intraoperative blood loss faster OR time shorter hospital stays less postoperative narcotic consumption no difference in effectiveness of decompression compared to open foraminotomy technique if anterior disc herniation is to be removed, then superior portion of inferior pedicle should be removed minimal nerve root retraction nerve root decompressed posteriorly, superiorly, and inferiorly pros & cons advantages avoids need for fusion avoids problems associated with anterior procedure disadvantages more difficult to remove discosteophyte complex disc height cannot be restored significant muscle pain and spasms (muscle splitting approach) significant bleeding (epidural vessels) inability to correct sagittal alignment Cervical disc arthroplasty approach Smith-Robinson anterior approach pros & cons avoids nonunion Complications Pseudarthrosis incidence 5-10% for single level fusions, 30% for multilevel fusions risk factors smoking diabetes multilevel fusions revision surgery treatment if asymptomatic, observe if symptomatic, treat with posterior cervical fusion or repeat anterior decompression and plating in patients with radiculopathy improved fusion rates seen with posterior fusion Recurrent laryngeal nerve injury (1%) most common nerve injury from this operation anatomic course of the nerve differs on the right and left side theoretically the nerve is at greater risk of injury with a right-sided approach, but there is no evidence to support a greater incidence of nerve injury with a right sided approach treatment initial treatment is observation if not improved over 6 weeks, then ENT consult to scope patient and inject Teflon same side approach should be used for revision cervical spine surgery Hypoglossal nerve injury a recognized complication after surgery in the upper cervical spine with an anterior approach tongue will deviate to side of injury Vascular injury vertebral artery injury (can be fatal) very rare injury aberrant vertebral artery path poses a greater risk for injury Dysphagia higher risk at higher levels (C3-4) risk can be minimized with the use of zero-profile anchored cages less prominence of anterior hardware reduces irritation and impingement of prevertebral structures, such as the esophagus Esophageal injury rare but devastating injuries early perforation (at the time of the procedure) usually caused by sharp instruments can be minimized by using dull retractors and avoiding excessive retraction should be repaired as soon as the injury is noticed late perforation usually from plate loosening or pullout technically difficult to repair requires a nasogastric tube and parenteral nutrition for a prolonged period Horner's syndrome characterized by ptosis, anhidrosis, miosis, enophthalmos, and loss of the ciliospinal reflex on the affected side of the face caused by injury to sympathetic chain, which sits on the lateral border of the longus coli muscle at C6 Adjacent segment disease Airway complications risk factors prolonged surgical duration (>5 hours) exposure above C4 >4 levels involved in fusion construct