Severe or progressive neurologic deficit or pain not responsive to nonsurgical management
Cervical spondylotic myelopathy due to degenerative process with aging, also associated with ossification of posterior longitudinal ligament (OPLL), hypertrophy of ligamentum flavum, or a congenitally narrowed cervical canal; other causes include trauma, instability, tumor, infection, epidural abscess, and kyphotic deformity
Early surgical management benefits severe or progressive myelopathy with concordant radiographic evidence of cord compression
Nonprogressive myelopathy with myelopathic symptoms and long-tract signs, Japanese Orthopaedic Association score less than 13 points, radiographic evidence of cord compression
Nonsurgical management not successful in reversing or permanently preventing progression of myelopathy
Secondary goals—Fusion to stabilize abnormal motion segments, neck pain relief, deformity correction
Advantages of anterior approach—Can directly decompress structures causing cord compression and nerve root impingement
Consider corpectomy over multilevel diskectomy in patient with two or three affected levels, developmental stenosis with osseous anterior-posterior canal diameter less than 13 mm, significant fixed cervical kyphosis, posterior osteophytes adjacent to end plate, or free disk fragment migrated posterior to vertebral body, or for significant component of spondylotic neck pain
Bone graft/interbody spacer needs to fuse two surfaces versus four in two-level anterior cervical diskectomy and fusion
Consider posterior approach when posterior compression results from buckling of hypertrophic ligamentum flavum or shingling of laminae in patients with hyperlordosis or in the setting of three or more affected levels in patients with no kyphotic deformity or neck pain
Authors prefer anterior surgery; advantages include lower risk of infection, more direct decompression, less postoperative pain
CT myelography when MRI cannot be obtained or images difficult to interpret
Plain CT—For fusion assessment, OPLL or ossification of ligamentum flavum, assessment of diffuse idiopathic skeletal hyperostosis and autofusion of segments, assessment of autofused facets
Angiography in tumor cases
Procedure
Patient Positioning
Supine position with arms tucked to sides; bump between scapulae; if iliac crest autograft used, bump underneath hip
For fibular strut autograft use, place thigh tourniquet with bump underneath ipsilateral hip
Transcranial motor- and somatosensory-evoked potentials to monitor spinal cord activity
For severe myelopathy, anesthetic protocol includes awake, fiberoptic, or nasotracheal intubation
Transient intravenous anesthesia to facilitate motor-evoked potential readings
Use 3-in silk tape to tape head to table to limit rotation
Apply Gardner-Wells tongs in corpectomies of three or more levels with initial traction of 15 lb of weight; review evoked potentials before proceeding
Tape shoulders to bottom of table with 3-in silk tape; avoid overpulling shoulders; traction brachial plexopathy can result
Determine width of vertebral body preoperatively on axial MRI or CT
Operating Microscope
Authors use operating microscope; loupe magnification with fiberoptic headlight also may be used
Microscope advantages over loupes—Magnification easily changed, magnification more powerful than loupe, enhanced lighting and visualization, allows co-surgeon to assist during difficult complication such as dural tear
Bring microscope into operating field after disk space localized with lateral image, usually from side of assisting surgeon
Approach
Smith-Robinson anteromedial approach for exposure of middle and lower cervical spine; authors prefer left-side approach but right or left can be used; approach may be dictated by prior anterior cervical exposure
For revision anterior cervical exposure, preoperative evaluation with direct laryngoscopy needed to identify residual vocal cord paralysis; if present, perform approach on same side as previous surgery; if no paralysis, approach from opposite side
Landmarks for Incision
Palpate surface landmarks when deciding incision location
Approximate level of incision by examining preoperative lateral image
Surgical Technique
Superficial Exposure
For single-level corpectomy, make 3- to 4-cm transverse incision beginning just past midline and extending to medial border of sternocleidomastoid (SCM) muscle
For multiple-level corpectomy, extend skin incision farther across midline to lateral border of SCM
Mark skin incision—Draw vertical lines every centimeter to serve as landmarks during closure
Infiltrate skin as superficially as possible using local anesthetic with epinephrine and 25-gauge needle
Take localizing radiograph
Incise skin with No. 10 blade; switch to electrocautery to incise subcutaneous tissue and divide platysma transversely
Incise fascia in interval between strap muscles and SCM using cautery followed by Metzenbaum scissors; develop interval with blunt finger dissection; palpate carotid pulse deep to SCM, delineating location of carotid sheath laterally and trachea and esophagus medially; perform blunt dissection through interval posteriorly toward midline to prevertebral fascia and longus colli muscle
Place appendiceal retractor to aid exposure
May retract omohyoid muscle medially with trachea or divide to improve exposure; identify it before starting deep dissection
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