Spine



Spine






Anterior Cervical Decompression/Discectomy

Indication and Goals: Anterior cervical decompression and/or discectomy is indicated in patients with symptomatic herniated and/or extruded vertebral discs (the soft cushion between the bony vertebral bodies) or cervical spondylosis (degeneration and stenosis [narrowing] of the neural foramen [windows where the nerve roots exit]) or stenosis of the spinal cord itself. Patients may have radiculopathy (nerve root dysfunction), myelopathy (spinal cord dysfunction), or long-tract signs (clumsiness, unsteadiness, bowel/bladder problems). Surgery may be indicated in patients with examination and imaging abnormalities, who have failed non-operative measures (therapy, traction, epidural injections, etc.). For symptomatic herniated discs, patients will often have radicular symptoms (pain, numbness, tingling that goes down the arm; weakness; loss of reflexes; etc.) that correspond to the level of the exiting root (the more distal level—i.e., a C5,6 herniated disc would affect the C6 nerve root on the side of the pathology). The goal of the procedure is to eliminate all symptoms and allow the athlete to return to his or her sport. This procedure is often combined with a fusion of the vertebral bodies above and below the affected disc (see Cervical Fusion). An anterior cervical approach is used for this procedure. This procedure is preferred over posterior cervical procedures in patients who have kyphosis (forward bending of the spine).

Procedure and Technique: A horizontal or oblique incision is made on the affected side of the neck based on the planned level. Landmarks are helpful in determining the location of this incision (Fig. 51A,B):















Bone/Cartilage


Level


Hyoid


C3/C4


Thyroid


C4/5


Cricoid


C7


The appropriate level is identified (usually with an intra-operative radiograph) and if needed, the two vertebral bodies can be distracted by placing temporary metal pins into the vertebral bodies or a lamina spreader between the vertebral bodies. This helps to improve access to the intervertebral discs (Fig. 51C-F). The affected disc is then removed (Fig. 51G,H) and the two vertebral levels are fused with the bone graft (Fig. 51I,J). The addition of spinal instrumentation may also be required and can help facilitate the rate of fusion and earlier return to function.

Post-surgical Precautions/Rehabilitation: Physical therapy may or may not be prescribed and will be based upon each individual patient. Hospital stay may be overnight, with early ambulation immediately following surgery. Some patients may be placed in a neck collar for comfort. Often times patients will experience some slight discomfort or pressure in the throat with swallowing and talking (dysphagia) that may last for a few weeks. Physical therapy consists of general range of motion and muscle strengthening around the shoulder and upper limb, interventions for pain reduction, localized inflammation, and education related to a safe return to work and/or activities of daily living. Patients may typically return to driving once off pain medicines and when they have regained neck motion. Restrictions on light lifting may vary, but typically may begin at 4 to 6 weeks. More aggressive lifting and sporting activity may resume at 3 to 6 months. During the course of formal rehabilitation, postural exercises can be implemented, as well as the addition of cardiovascular conditioning.

Expected Outcomes: A modification of job tasks may be suggested prior to a return to work based upon one’s ability to recover from surgery and present with a good prognosis for limited recurrence of symptoms.

Return to Play: Return to play is typically based on the number of levels fused (see Cervical Fusion). Athletes with one-level fusions may return to play after complete healing—typically this is a season-ending surgery. Flexion-extension films should be taken to ensure spinal stability. Multiple-level fusions typically preclude participation.



Recommended Readings

Erickson M, Fites BS, Thieken MT, McGee AW. Outpatient anterior cervical discectomy and fusion. Am J Orthop. 2007;36(8):429-432.

Fountas KN, Kapsalaki EZ, Nikolakakos LG, Smisson HF, Johnston KW, Grigorian AA, Lee GP, Robinson JS Jr. Anterior cervical discectomy and fusion associated complications. Spine (Phila Pa 1976). 2007(1);32(21):2310-2317. Review.

Mobbs RJ, Rao P, Chandran NK. Anterior cervical discectomy and fusion: Analysis of surgical outcome with and without plating. J Clin Neurosci. 2007;14(7):639-642.







Figure 53. Anterior Approach to Cervical Spine. A: Superficial cervical spine landmarks correlate with cervical disc spaces. Hyoid bone (C3-4), thyroid cartilage (C4-5), carotid tubercle (C6) and cricoid cartilage (C7). B: Anterior cervical approach skin incision is most often left sided continuing through the platysma. C: Uncinate upslope is defined during discectomy. D: Disc is removed to the level of the posterior longitudinal ligament (PLL). E, F: Distraction of the disc space can be performed to improve visualization, restore neuroforaminal height, and relieve buckling of the PLL. G, H: In cases of extruded disc herniations, a rent in the PLL can be identified and fragments removed. I, J: The graft is then sized and inserted with or without instrumentation.







Figure 53. (continued)







Figure 53. (continued)



Posterior Cervical Decompression/Discectomy

Indications and Goals: Indications for posterior cervical decompression/discectomy are similar to those for anterior cervical decompression and discectomy. A posterior approach is usually favored for cervical discs that are located more laterally without substantial bony involvement. The procedure is also more commonly utilized for patients with normal or lordotic (backward bending) cervical spine alignment. In patients with a more centrally located herniation, or if the narrowing is secondary to anteriorly located bony spurs, then an anterior cervical decompression/discectomy may be better.

Procedure and Technique: A posterior midline approach is used centered on the affected level(s) (Fig. 52A,B). Radiographic conformation of the planned level is usually done intra-operatively. The paraspinal muscles are stripped off the posterior elements of the vertebrae and the lateral aspects of the lamina and foramen are widened with various punches and gouges (laminoforaminotomy) (Fig. 52C,D). This allows inspection and decompression of the affected exiting nerve roots. Alternatively, if there is multilevel compression and/or central compression posteriorly, then removal of the entire bony arch may be necessary (laminectomy). In patients who undergo a laminoforaminotomy, if 50% of the facet (joint between two vertebrae) is preserved, then no fusion is required. In patients who undergo a laminectomy, the resulting instability typically requires fusion of the affected level(s). This is performed by adding bone graft and sometimes instrumentation (screws and rods) to stabilize the vertebral segment(s) (see Cervical Fusion).

Post-surgical Precautions/Rehabilitation: Physical therapy may or may not be prescribed and will be based upon each individual patient. The length of hospital stay may be a few days depending on the procedure; however, early ambulation immediately following surgery is still recommended. The patient will likely have a neck brace for comfort post-operatively. Formal rehabilitation may be necessary depending on the number of levels addressed and include patient education. Range of motion will be limited early on to allow for the bone graft and implants to undergo healing. Gradual and supervised range of motion may typically begin between weeks 4 and 6, but communication with the surgeon should confirm since some patients may be allowed to be mobilized earlier while others may require additional stabilization and healing time.

Expected Outcomes: Functional activities such as driving may take up to 6 weeks, and a return to work may take a few weeks to a few months based upon the physical requirements of the job or activity.

Return to Play: If no fusion is required, athletes may return to competition as soon as the soft tissue has healed, 6 to 8 weeks typically. Return to play varies on the number of levels involved in patients who require a fusion (see Cervical Fusion).



Recommended Readings

Dvorak MF, Fisher CG, Fehlings MG, Rampersaud YR, Oner FC, Aarabi B, Vaccaro AR. The surgical approach to subaxial cervical spine injuries: An evidence-based algorithm based on the SLIC classification system. Spine (Phila Pa 1976). 2007;32(23):2620-2629.

Liu P, Zhao J, Liu F, Liu M, Fan W. A novel operative approach for the treatment of old distractive flexion injuries of subaxial cervical spine. Spine (Phila Pa 1976). 2008;33(13):1459-1464.







Figure 54. Posterior Cervical Spine Approach. A: Posterior longitudinal incision is made over the spinous processes. B: The posterior spine is exposed. C: Keyhole laminoforaminotomy is performed at the junction of the lamina and facet joint. D: Lateral disc herniations can be accessed posteriorly by carefully retracting the cervical nerve root. However, the spinal cord itself should not be manipulated.



Cervical Fusion

Indications and Goals: Cervical fusion is indicated for the management of spinal deformity, infection, tumor reconstruction, and stabilization of unstable vertebral segments resulting from trauma, various destructive processes (tumors, arthritides, etc.) and surgically induced instability. The goal is to achieve a solid arthrodesis between two affected vertebral bodies/segment(s) at the expense of some loss of motion. A secondary goal is to maintain spinal mobility by attempting to limit the number of levels fused whenever possible. Cervical fusion can be performed from either an anterior, posterior, or combined anterior and posterior approaches, depending on a variety of factors.

Procedure and Technique: Anterior and/or posterior approaches are made as described previously. For anterior cervical fusions, once the discectomy and/or corpectomy with the associated disc(s) have been removed, a cervical fusion is performed by placing the bone graft within the space created. During the discectomy(ies), the cartilaginous endplates of the corresponding superior and inferior discs are removed as well (Fig. 53A). The subchondral bone is preserved if possible to allow for a bony endplate for the cervical fusion and to reduce the risk of graft subsidence (Fig. 53B). This is typically performed with either structural autologous tricortical iliac crest graft (Smith-Robinson technique) or with allograft (Fig. 53C). For multilevel corpectomies, a fibular strut allograft is typically used. In unusual cases of extremely long constructs, patient request and/or surgeon preference, a structural cage filled with autograft bone can be used instead. The use of an anterior cervical plate is individualized (Fig. 53D) on the basis of the patient and pathology addressed, but is more common in the case after multilevel decompressions; however, its use even in single-level fusions can help patients return to activity more quickly and reduce or eliminate the need for post-operative external immobilization.

For posterior fusions, the posterior elements, in particular the facet joints and intervening spinous process and lamina, are decorticated and the graft is laid onto the opposing surfaces. Segmental fixation with instrumentation either in the lateral masses or spinous processes and less commonly in the lamina or pedicle may be added in selected cases (Fig. 54).

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Jul 9, 2020 | Posted by in SPORT MEDICINE | Comments Off on Spine
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