- Email: [email protected]
Posterior Cervical Endoscopic Laminoforaminotomy for the Treatment of Radiculopathy in the Athlete
Posterior Cervical Endoscopic Laminoforaminotomy for the Treatment of Radiculopathy in the Athlete Tim E. Adamson, MD The cervical endoscopic laminoforaminotomy was initially developed in 1987 and has been very effective when applied to the treatment of unilateral cervical radiculopathy. Utilizing this minimally invasive non-fusion technique, many amateur and professional athletes have been able to return to full activity quicker and with fewer restrictions than with many other techniques. The selection criteria, surgical technique, and postoperative course are discussed in detail. Oper Tech Sports Med 13:96-100 © 2005 Elsevier Inc. All rights reserved. KEYWORDS cervical radiculopathy, cervical spondylosis, endoscopic surgery, laminectomy, minimally invasive surgery, return to play
T
he surgical treatment of cervical radiculopathy has been practiced for at least 60 years. The initial experience obtained by Frykholm1 and Semmes and Murphy2 became the cornerstone of treatment using the posterior approach to the cervical spine and creating a laminoforaminotomy for removal of a disk herniation or decompression of a spondylotic foramen. The early results obtained by these pioneers have been difficult to surpass even with the advances of surgical technique and technology over the ensuing decades.3-5 As experience was gained with the cervical laminoforaminotomy, it rapidly became apparent that myelopathy and spine-alignment abnormalities could not be adequately treated. As an answer to these limitations, the anterior approach to the cervical spine was developed and validated by Robinson and Smith6 and Cloward.7 In part because of the ability to treat almost all forms of myelopathy and radiculopathy with a single approach, the anterior approach became the mainstay for most spine surgeons. However, as experience was gained with the anterior approach, its limitations became apparent. The consequences of fusing a motion segment were followed as the concept of “adjacent level disease” evolved.8-10 In addition, the unique complications of the anterior dissection, such as laryngeal nerve injury, vascular injury, and esophageal injury, were identified.11 Considering these factors, a group of spine surgeons continued to rely on the open posterior cervical laminoforaminotomy for those patients Carolina Neurosurgery and Spine Associates, Charlotte, NC. Address reprint requests to Tim E. Adamson, MD, Carolina Neurosurgery and Spine Associates, 1010 Edgehill Road North, Charlotte, NC 28203. E-mail: [email protected]
96
1060-1872/05/$-see front matter © 2005 Elsevier Inc. All rights reserved. doi:10.1053/j.otsm.2005.08.003
with strictly a radiculopathy without alignment abnormalities or myelopathy and obtained good results without the consequences of the anterior approach or fusion.12 In 1997, after the introduction of the lumbar microendoscopic diskectomy by Smith and Foley,13 we adapted the set to begin trials for posterior cervical endoscopic laminoforaminotomy (CELF). Since that time, over 600 patients have undergone treatment of cervical radiculopathy with CELF with good relief of symptoms and very quick return to full activity without the potential consequences of an anterior approach and fusion. After evaluating our initial experience with CELF,14,15 the advantages of biomechanical stability, no alteration in motion segments, and a rapid return to full activity including strenuous occupations, it became apparent that athletes, both professional and amateur could benefit from the CELF. Described later are the current selection criteria, surgical technique, and outcomes of our experience.
Diagnosis The workup and evaluation of cervical radiculopathy can vary from simple to extremely complex depending on the clinical findings and imaging studies. This is compounded by the athlete involved in contact sports. Distinguishing a brachial plexus stretch “stinger” from a cervical radiculopathy can be challenging. The purity of single nerve root involvement is often helpful, as is being able to review the impact resulting in the injury. Impact with the head away from the affected arm is commonly associated with a “stinger.” Impact with the head toward the affected arm is associated with
Treatment of radiculopathy cervical nerve root compression, either from foramenal stenosis or disk herniation. Localizing the symptoms to a specific root level is facilitated by the presence of objective motor, sensory, and reflex changes. Frequently, the roots with representation into the hand (C6, C7, C8) are easier to identify than those represented in the shoulder (C4 and sometimes C5). Once a cervical radiculopathy is suspected, imaging plays a very important role. Magnetic resonance imaging (MRI) is usually the first study obtained unless a fracture is suspected. A good MRI will allow visualization of the spinal canal, spinal cord, and disk spaces. However, it is not uncommon to find MRI images inadequate to evaluate for spondylosis and disk herniations contained within the foramen. MRI also may exaggerate the appearance of central canal stenosis. An intravenous-contrasted computed tomography scan can be useful to further clarify foramenal anatomy. It is not uncommon for the images on large muscular athletes to be degraded by size. In this setting and when the physical findings do not match the imaging findings, a myelogram and computed tomography scan is recommended. This allows not only a better assessment of central canal size but when combined with flexion and extension views may be used to rule out dynamic changes that may be missed on static supine images.
Nonsurgical Treatment Nonsurgical treatment options should always be the first line of treatment unless weakness is profound or neurologic deficits progress during conservative therapy. Anti-inflammatories and oral steroids play an important role in the acute treatment of radiculopathy. The rapid institution of physical therapy and traction for mobilization may be extremely helpful. The majority of acute radiculopathies will resolve with these measures. The introduction of long-term core strengthening to prevent recurrent injury then becomes very important. When radicular signs and symptoms do not respond, the patient should be considered for surgical options. Equally important in the competitive athlete is the impact of a prolonged loss of training or competition time. The presence of ongoing weakness also becomes an important factor and can speed up the surgical decision.
Selection Criteria for CELF Once it has become apparent that the patient/athlete is going to require surgical treatment of a cervical radiculopathy, it is useful to identify those who are candidates for CELF. The primary exclusion is the presence of symptomatic canal stenosis or myelopathy because this is not adequately treated with a laminoforaminotomy. Any patients with alignment abnormalities or instability on dynamic views are also excluded. In general, a unilateral radiculopathy involving 1 or 2 root levels can be considered. Imaging studies should confirm a concordant finding of lateral spinal canal or foramenal com-
97
Figure 1 The patient is placed in the sitting position with the head secured in the Mayfield-Kees headholder. The C-arm unit is then brought in from the feet.
pression on the affected nerve root. The presence of spondylotic spur formation versus soft-disk herniation does not make a difference in the overall surgical outcome. The presence of a prior central laminectomy or anterior fusion has not been a contraindication. However, any prior laminoforaminotomy at the affected level is a contraindication because of the risk of docking the cylindrical retractor over the exposed nerve root (Figs. 1-5).
Positioning and Anesthesia Considerations After the induction of general endotracheal anesthesia, the patient is carefully placed in the sitting position with the head secured in a Mayfield-Kees headholder. Although this requires 3 additional puncture wounds in the scalp, the risk of ocular or facial pressure injury is minimized. Slowly adjusting the bed into the sitting position and providing a small intravenous bolus of saline will minimize most blood pressure changes. A precordial Doppler is used on all cases, but a central venous line is not used unless presurgical medical comorbidities require it. The sitting position has provided the best view for localization of the operative level with fluoroscopy by allowing gravity to drop the shoulders. Additionally, it provides the best way to keep the operative field clear of what can sometimes be challenging epidural venous oozing. Once positioned, careful attention is placed on ensuring all exposed neurovascular prominences are protected (eg, ulnar nerves). The preferred positioning is almost a “recliner” position with the legs flexed at the knees and hips (Fig. 1). The neck is maintained in a neutral position without excessive rotation, flexion, or extension. The C-arm fluoroscopy unit is the brought in from the front and slightly off to the side of the patient to provide a true lateral image of the C-spine (Fig. 1).
T.E. Adamson
98
Figure 2 Using fluoroscopic guidance, the dilator system is initially directed to the lateral mass and lamina junction of the cephalad vertebral body. The larger dilators and the cylindrical retractor are the positioned over the facet complex with fluoroscopic confirmation.
Surgical Technique After formal prepping and draping of the posterior neck, a spinal needle is used to localize the target level with fluoroscopy. The ideal trajectory is to enter the skin just below the targeted level providing a slight upward slant to the retractor system, which allows free drainage of irrigation fluid and blood. The goal is to enter the skin directly posterior to the facet complex. This is accomplished by starting the skin entry 1½ to 2 cm lateral to the palpable midline. After selecting the appropriate entry point, a 16-mm incision is created 30° to 45° off the horizontal plane to take advantage of the Langer lines on the back of the neck. This facilitates wound healing by minimizing tension across the incision. A K-wire is then introduced through the incision to the back of the lateral mass of the cephalad vertebra of the target level under fluoroscopic guidance. By targeting the
Figure 3 Once the retractor is securely fastened to the table attachment, the endoscope is attached with the camera cephalad and out of the way.
lateral mass 5 to 10 mm cephalad from the targeted disk space, the potential risk of passing through the interlaminar space overlying the disk space is reduced (Fig. 2). The first dilator is passed along the K-wire to dock securely on the bone (Fig. 2). The K-wire is removed, and the dilator is used to create a subperiosteal dissection from the entry point caudally to include the facet complex, which can be easily palpated with the dilator by its characteristic step. This step is important to minimize the amount of soft tissue removed to visualize the facet once the endoscope is brought into use. Before proceeding with the next 3 dilators, it is helpful to pass a hemostat or scissors in the closed position along the outside of the first dilator and carefully spread the deep fascia. This simplifies passing the remaining dilators and the
Figure 4 After removal of the overlying soft tissue, the junction of the lamina and the articular process of the facet are visualized. In this example, the exposure is at C-7/T-1 with its characteristically flatter junction.
Treatment of radiculopathy
Figure 5 After completion of the laminoforaminotomy and removal of the disk fragment, the lateral thecal sac and nerve root are clearly seen.
cylindrical retractor. Fluoroscopy is used to monitor placement of the remaining dilators and the cylindrical retractor. Once the retractor is confirmed in the proper location, it is anchored to the table and the dilators removed (Fig. 3). After removal of some of the soft tissue overlying the facet, the microendoscope is positioned in the cylindrical retractor. Early visual identification of the bone speeds the removal of the remainder of the soft tissue blocking clear visualization of the facet. At this point, the lamina facet junction can frequently be seen, providing a clue to the location of the lateral canal (Fig. 4). If this landmark is not clearly seen as can sometimes occur with spondylosis and “shingling” of the lamina, it is helpful to trend more medial to create more of a laminotomy over the canal rather than inadvertently disrupting facet that should be left intact. A long-handled fine-tip drill is then used to initiate the laminoforaminotomy. The bone is carefully thinned over the lateral lamina and medial facet until a small opening to the epidural space is created usually over the lateral canal. Thin-footed 1- and 2-mm Kerrisons are then used to widen out the exposure to visualize the underlying thecal sac and nerve. At this point, identification of the caudal pedicle is mandatory. It is the only way to determine whether the foramen is adequately decompressed and to avoid resection of more than one third to two thirds of the medial facet. Resecting bone down to the cephalad aspect of the pedicle and just until the lateral margin of the pedicle can be palpated ensures a complete medial foraminal decompression without destabilizing the facet. In those cases being treated for spondylotic foramenal stenosis, the procedure is essentially complete at this point. It is helpful to pass a nerve hook out the remaining foramen to ensure adequate decompression. Those cases of soft-disk herniation allow removal of the offending fragments by gaining access under the axilla of the
99 decompressed nerve root. By passing a nerve hook inferiorly along the medial aspect of the pedicle, a clear plane under the thecal sac can be created by carefully rotating the hook medially until almost vertical. A disk herniation can be palpated and frequently mobilized back toward the axilla where it can be removed with a micropituitary ronguer. Contained herniations will frequently require the use of a down-angle microcurette to mobilize the fragments, which may then be removed via the axilla. To prevent inadvertent trauma to the nerve root, it is important to complete the laminoforaminotomy and posterior decompression of the root before attempting to retract the root and gain access to the floor of the canal. Additionally, it is not uncommon to find the nerve roots split into sensory and motor components in separate dural sleeves, especially at the lower levels of the cervical spine. To avoid retracting only the more superficial sleeve and possibly traumatizing the deeper sleeve, it is important to always begin retracting under the thecal sac caudal to the take off of the root sleeve. The nerve hook can then be rotated medially and then cephalad under both sleeves before retracting the root cephalad. Because of the anatomy of the C5 root and its very tight straight course over the top of the C5 pedicle, it is important to minimize all manipulation. Careless dissection and sometimes even just bad luck can result in a motor deficit that may require months to fully resolve. Once the decompression and diskectomy have been completed, hemostasis is obtained and the wound copiously irrigated with saline. A pledget of methylprednisolone acetate– soaked Gelfoam (Pharmacia, Kalamazoo, MI) is the placed over the exposed nerve root. The wound is closed in 2 layers with interrupted resorbable sutures in the subcutaneous fascia and in the subdermal layer. A long-acting local anesthetic is infiltrated around the incision for postoperative analgesia and the skin edge sealed with Dermabond (Ethicon, Somerville, NJ).
Postoperative Care and Return to Activity Once the patient has fully emerged from anesthesia and voiding well, they are discharged to home; this averages 3 hours. After 3 to 5 days, the incisional soreness has usually resolved and most patients resume normal activity but not strenuous activity. Mobilization and stretching then begin, and after an additional week most patients are at or near full activity. The competitive athlete may be accelerated because of better than average healing times. We have returned many athletes to aerobic conditioning within 2 to 3 days. Physical therapy for neck mobilization can begin about the same time. If there are no issues of persisting weakness, the patient may resume resistance training at 7 days. For those athletes competing in contact sports, we have allowed a return to full contact once strength has normalized and soreness has resolved. In our experience, this has varied from 2½ weeks to 6 weeks.
T.E. Adamson
100
Results Over the past 7 years, over 600 patients have been personally treated using the CELF technique. Our general results have been encouraging and are fully described elsewhere.14,15 Many of these patients were athletes pursuing a variety of competitive sports, amateur and professional. Interesting subgroups to look at are those athletes involved in highimpact professional sports, which continue to expose the athlete to high levels of stress or the cervical spine. Ten patients that fall into that category were treated over that time period (8 professional football players and 2 professional race car drivers). Both drivers were treated in the off season and returned to driving within 4 weeks. The football players form a more heterogeneous group with differing levels of preoperative deficits. Seven players returned to play at full capacity once preoperative motor deficits had cleared. One of these players with multilevel spondylotic disease required additional surgery 1½ years postoperatively and retired from competition. The one athlete who never returned to playing sustained a game-related complete C5 deficit secondary to spondylotic foramenal stenosis. His motor deficit never improved enough to return to full capacity.
Conclusions The posterior CELF has proven itself as a safe and effective surgical treatment for unilateral cervical radiculopathy in the general patient population. It has provided good relief of radiculopathy pain and deficits and minimized postoperative recovery times without altering the cervical motion segments, thereby eliminating increased strain on adjacent levels. These same features have made the procedure very attractive to competitive athletes, especially those for whom it is a profession. In many ways, they are the ideal patient with their motivation to recover and resume training. The extraordinary stresses of some sports such as football and car racing have been generally well tolerated once back to full capacity.
Although the CELF procedure can be challenging to master, it provides many advantages for the athlete in general.
Acknowledgments The author would like to thank Christine Renda for her assistance in preparation of the manuscript.
References 1. Frykholm R: Cervical root compression resulting from disc degeneration and root sleeve fibrosis. Acta Chir Scand 160:1-149, 1951 2. Semmes RE, Murphy F: Syndrome of unilateral rupture of the sixth cervical intervertebral disc, with compression of the seventh cervical nerve root. Report of four cases with symptoms simulating coronary disease. JAMA 121:1209-1214, 1943 3. Zeidman SM, Ducker TB: Posterior cervical laminoforaminotomy for radiculopathy: Review of 172 cases. Neurosurgery 33:356-362, 1993 4. Williams RW: Microcervical foraminotomy. A surgical alternative for intractable radicular pain. Spine 8:708-716, 1983 5. Baba G. Furusawa N, Imura S, et al: Late radiographic findings after anterior cervical fusion for spondylotic myeloradiculopathy. Spine 18: 2167-2173, 1993 6. Robinson RA, Smith GW: Anterolateral cervical disc removal and interbody fusion for cervical disc syndrome. Bull John Hopkins Hospital 96:223, 1955 7. Cloward R: The anterior approach for removal of ruptured cervical discs. J Neurosurg 15:602-617, 1958 8. DePalma AF, Rothman RH, Lewinnek GE, et al: Anterior interbody fusion for severe cervical disc degeneration. Surg Gynecol Obstet 134: 755-758, 1972 9. Pospiech J, Stolke D, Wilke HJ, et al: Intradiscal pressure recordings in the cervical spine. Neurosurgery 44:379-385, 1999 10. Hilibrand AS, Yoo JU, Carlson GD, et al: The success of anterior cervical arthrodesis adjacent to a previous fusion. Spine 22:1574-1579, 1997 11. Flynn TB: Neurological complication of anterior cervical interbody fusion. Spine 7:536-539, 1982 12. Simeone F, Dillin W: Treatment of cervical disc disease: selection of operative approach. Contemp Neurosurg 8:1-6, 1986 13. Smith M, Foley K: Microendoscopic discectomy. Tech Neurosurg 3:301-307, 1997 14. Adamson T: Microendoscopic posterior cervical laminoforaminotomy for unilateral radiculopathy: results of a new technique in 100 cases. J Neurosurg Spine 95:51-57, 2001 15. Adamson, T: The impact of minimally invasive cervical spine surgery. J Neurosurg Spine 1:43-46, 2004
T
he surgical treatment of cervical radiculopathy has been practiced for at least 60 years. The initial experience obtained by Frykholm1 and Semmes and Murphy2 became the cornerstone of treatment using the posterior approach to the cervical spine and creating a laminoforaminotomy for removal of a disk herniation or decompression of a spondylotic foramen. The early results obtained by these pioneers have been difficult to surpass even with the advances of surgical technique and technology over the ensuing decades.3-5 As experience was gained with the cervical laminoforaminotomy, it rapidly became apparent that myelopathy and spine-alignment abnormalities could not be adequately treated. As an answer to these limitations, the anterior approach to the cervical spine was developed and validated by Robinson and Smith6 and Cloward.7 In part because of the ability to treat almost all forms of myelopathy and radiculopathy with a single approach, the anterior approach became the mainstay for most spine surgeons. However, as experience was gained with the anterior approach, its limitations became apparent. The consequences of fusing a motion segment were followed as the concept of “adjacent level disease” evolved.8-10 In addition, the unique complications of the anterior dissection, such as laryngeal nerve injury, vascular injury, and esophageal injury, were identified.11 Considering these factors, a group of spine surgeons continued to rely on the open posterior cervical laminoforaminotomy for those patients Carolina Neurosurgery and Spine Associates, Charlotte, NC. Address reprint requests to Tim E. Adamson, MD, Carolina Neurosurgery and Spine Associates, 1010 Edgehill Road North, Charlotte, NC 28203. E-mail: [email protected]
96
1060-1872/05/$-see front matter © 2005 Elsevier Inc. All rights reserved. doi:10.1053/j.otsm.2005.08.003
with strictly a radiculopathy without alignment abnormalities or myelopathy and obtained good results without the consequences of the anterior approach or fusion.12 In 1997, after the introduction of the lumbar microendoscopic diskectomy by Smith and Foley,13 we adapted the set to begin trials for posterior cervical endoscopic laminoforaminotomy (CELF). Since that time, over 600 patients have undergone treatment of cervical radiculopathy with CELF with good relief of symptoms and very quick return to full activity without the potential consequences of an anterior approach and fusion. After evaluating our initial experience with CELF,14,15 the advantages of biomechanical stability, no alteration in motion segments, and a rapid return to full activity including strenuous occupations, it became apparent that athletes, both professional and amateur could benefit from the CELF. Described later are the current selection criteria, surgical technique, and outcomes of our experience.
Diagnosis The workup and evaluation of cervical radiculopathy can vary from simple to extremely complex depending on the clinical findings and imaging studies. This is compounded by the athlete involved in contact sports. Distinguishing a brachial plexus stretch “stinger” from a cervical radiculopathy can be challenging. The purity of single nerve root involvement is often helpful, as is being able to review the impact resulting in the injury. Impact with the head away from the affected arm is commonly associated with a “stinger.” Impact with the head toward the affected arm is associated with
Treatment of radiculopathy cervical nerve root compression, either from foramenal stenosis or disk herniation. Localizing the symptoms to a specific root level is facilitated by the presence of objective motor, sensory, and reflex changes. Frequently, the roots with representation into the hand (C6, C7, C8) are easier to identify than those represented in the shoulder (C4 and sometimes C5). Once a cervical radiculopathy is suspected, imaging plays a very important role. Magnetic resonance imaging (MRI) is usually the first study obtained unless a fracture is suspected. A good MRI will allow visualization of the spinal canal, spinal cord, and disk spaces. However, it is not uncommon to find MRI images inadequate to evaluate for spondylosis and disk herniations contained within the foramen. MRI also may exaggerate the appearance of central canal stenosis. An intravenous-contrasted computed tomography scan can be useful to further clarify foramenal anatomy. It is not uncommon for the images on large muscular athletes to be degraded by size. In this setting and when the physical findings do not match the imaging findings, a myelogram and computed tomography scan is recommended. This allows not only a better assessment of central canal size but when combined with flexion and extension views may be used to rule out dynamic changes that may be missed on static supine images.
Nonsurgical Treatment Nonsurgical treatment options should always be the first line of treatment unless weakness is profound or neurologic deficits progress during conservative therapy. Anti-inflammatories and oral steroids play an important role in the acute treatment of radiculopathy. The rapid institution of physical therapy and traction for mobilization may be extremely helpful. The majority of acute radiculopathies will resolve with these measures. The introduction of long-term core strengthening to prevent recurrent injury then becomes very important. When radicular signs and symptoms do not respond, the patient should be considered for surgical options. Equally important in the competitive athlete is the impact of a prolonged loss of training or competition time. The presence of ongoing weakness also becomes an important factor and can speed up the surgical decision.
Selection Criteria for CELF Once it has become apparent that the patient/athlete is going to require surgical treatment of a cervical radiculopathy, it is useful to identify those who are candidates for CELF. The primary exclusion is the presence of symptomatic canal stenosis or myelopathy because this is not adequately treated with a laminoforaminotomy. Any patients with alignment abnormalities or instability on dynamic views are also excluded. In general, a unilateral radiculopathy involving 1 or 2 root levels can be considered. Imaging studies should confirm a concordant finding of lateral spinal canal or foramenal com-
97
Figure 1 The patient is placed in the sitting position with the head secured in the Mayfield-Kees headholder. The C-arm unit is then brought in from the feet.
pression on the affected nerve root. The presence of spondylotic spur formation versus soft-disk herniation does not make a difference in the overall surgical outcome. The presence of a prior central laminectomy or anterior fusion has not been a contraindication. However, any prior laminoforaminotomy at the affected level is a contraindication because of the risk of docking the cylindrical retractor over the exposed nerve root (Figs. 1-5).
Positioning and Anesthesia Considerations After the induction of general endotracheal anesthesia, the patient is carefully placed in the sitting position with the head secured in a Mayfield-Kees headholder. Although this requires 3 additional puncture wounds in the scalp, the risk of ocular or facial pressure injury is minimized. Slowly adjusting the bed into the sitting position and providing a small intravenous bolus of saline will minimize most blood pressure changes. A precordial Doppler is used on all cases, but a central venous line is not used unless presurgical medical comorbidities require it. The sitting position has provided the best view for localization of the operative level with fluoroscopy by allowing gravity to drop the shoulders. Additionally, it provides the best way to keep the operative field clear of what can sometimes be challenging epidural venous oozing. Once positioned, careful attention is placed on ensuring all exposed neurovascular prominences are protected (eg, ulnar nerves). The preferred positioning is almost a “recliner” position with the legs flexed at the knees and hips (Fig. 1). The neck is maintained in a neutral position without excessive rotation, flexion, or extension. The C-arm fluoroscopy unit is the brought in from the front and slightly off to the side of the patient to provide a true lateral image of the C-spine (Fig. 1).
T.E. Adamson
98
Figure 2 Using fluoroscopic guidance, the dilator system is initially directed to the lateral mass and lamina junction of the cephalad vertebral body. The larger dilators and the cylindrical retractor are the positioned over the facet complex with fluoroscopic confirmation.
Surgical Technique After formal prepping and draping of the posterior neck, a spinal needle is used to localize the target level with fluoroscopy. The ideal trajectory is to enter the skin just below the targeted level providing a slight upward slant to the retractor system, which allows free drainage of irrigation fluid and blood. The goal is to enter the skin directly posterior to the facet complex. This is accomplished by starting the skin entry 1½ to 2 cm lateral to the palpable midline. After selecting the appropriate entry point, a 16-mm incision is created 30° to 45° off the horizontal plane to take advantage of the Langer lines on the back of the neck. This facilitates wound healing by minimizing tension across the incision. A K-wire is then introduced through the incision to the back of the lateral mass of the cephalad vertebra of the target level under fluoroscopic guidance. By targeting the
Figure 3 Once the retractor is securely fastened to the table attachment, the endoscope is attached with the camera cephalad and out of the way.
lateral mass 5 to 10 mm cephalad from the targeted disk space, the potential risk of passing through the interlaminar space overlying the disk space is reduced (Fig. 2). The first dilator is passed along the K-wire to dock securely on the bone (Fig. 2). The K-wire is removed, and the dilator is used to create a subperiosteal dissection from the entry point caudally to include the facet complex, which can be easily palpated with the dilator by its characteristic step. This step is important to minimize the amount of soft tissue removed to visualize the facet once the endoscope is brought into use. Before proceeding with the next 3 dilators, it is helpful to pass a hemostat or scissors in the closed position along the outside of the first dilator and carefully spread the deep fascia. This simplifies passing the remaining dilators and the
Figure 4 After removal of the overlying soft tissue, the junction of the lamina and the articular process of the facet are visualized. In this example, the exposure is at C-7/T-1 with its characteristically flatter junction.
Treatment of radiculopathy
Figure 5 After completion of the laminoforaminotomy and removal of the disk fragment, the lateral thecal sac and nerve root are clearly seen.
cylindrical retractor. Fluoroscopy is used to monitor placement of the remaining dilators and the cylindrical retractor. Once the retractor is confirmed in the proper location, it is anchored to the table and the dilators removed (Fig. 3). After removal of some of the soft tissue overlying the facet, the microendoscope is positioned in the cylindrical retractor. Early visual identification of the bone speeds the removal of the remainder of the soft tissue blocking clear visualization of the facet. At this point, the lamina facet junction can frequently be seen, providing a clue to the location of the lateral canal (Fig. 4). If this landmark is not clearly seen as can sometimes occur with spondylosis and “shingling” of the lamina, it is helpful to trend more medial to create more of a laminotomy over the canal rather than inadvertently disrupting facet that should be left intact. A long-handled fine-tip drill is then used to initiate the laminoforaminotomy. The bone is carefully thinned over the lateral lamina and medial facet until a small opening to the epidural space is created usually over the lateral canal. Thin-footed 1- and 2-mm Kerrisons are then used to widen out the exposure to visualize the underlying thecal sac and nerve. At this point, identification of the caudal pedicle is mandatory. It is the only way to determine whether the foramen is adequately decompressed and to avoid resection of more than one third to two thirds of the medial facet. Resecting bone down to the cephalad aspect of the pedicle and just until the lateral margin of the pedicle can be palpated ensures a complete medial foraminal decompression without destabilizing the facet. In those cases being treated for spondylotic foramenal stenosis, the procedure is essentially complete at this point. It is helpful to pass a nerve hook out the remaining foramen to ensure adequate decompression. Those cases of soft-disk herniation allow removal of the offending fragments by gaining access under the axilla of the
99 decompressed nerve root. By passing a nerve hook inferiorly along the medial aspect of the pedicle, a clear plane under the thecal sac can be created by carefully rotating the hook medially until almost vertical. A disk herniation can be palpated and frequently mobilized back toward the axilla where it can be removed with a micropituitary ronguer. Contained herniations will frequently require the use of a down-angle microcurette to mobilize the fragments, which may then be removed via the axilla. To prevent inadvertent trauma to the nerve root, it is important to complete the laminoforaminotomy and posterior decompression of the root before attempting to retract the root and gain access to the floor of the canal. Additionally, it is not uncommon to find the nerve roots split into sensory and motor components in separate dural sleeves, especially at the lower levels of the cervical spine. To avoid retracting only the more superficial sleeve and possibly traumatizing the deeper sleeve, it is important to always begin retracting under the thecal sac caudal to the take off of the root sleeve. The nerve hook can then be rotated medially and then cephalad under both sleeves before retracting the root cephalad. Because of the anatomy of the C5 root and its very tight straight course over the top of the C5 pedicle, it is important to minimize all manipulation. Careless dissection and sometimes even just bad luck can result in a motor deficit that may require months to fully resolve. Once the decompression and diskectomy have been completed, hemostasis is obtained and the wound copiously irrigated with saline. A pledget of methylprednisolone acetate– soaked Gelfoam (Pharmacia, Kalamazoo, MI) is the placed over the exposed nerve root. The wound is closed in 2 layers with interrupted resorbable sutures in the subcutaneous fascia and in the subdermal layer. A long-acting local anesthetic is infiltrated around the incision for postoperative analgesia and the skin edge sealed with Dermabond (Ethicon, Somerville, NJ).
Postoperative Care and Return to Activity Once the patient has fully emerged from anesthesia and voiding well, they are discharged to home; this averages 3 hours. After 3 to 5 days, the incisional soreness has usually resolved and most patients resume normal activity but not strenuous activity. Mobilization and stretching then begin, and after an additional week most patients are at or near full activity. The competitive athlete may be accelerated because of better than average healing times. We have returned many athletes to aerobic conditioning within 2 to 3 days. Physical therapy for neck mobilization can begin about the same time. If there are no issues of persisting weakness, the patient may resume resistance training at 7 days. For those athletes competing in contact sports, we have allowed a return to full contact once strength has normalized and soreness has resolved. In our experience, this has varied from 2½ weeks to 6 weeks.
T.E. Adamson
100
Results Over the past 7 years, over 600 patients have been personally treated using the CELF technique. Our general results have been encouraging and are fully described elsewhere.14,15 Many of these patients were athletes pursuing a variety of competitive sports, amateur and professional. Interesting subgroups to look at are those athletes involved in highimpact professional sports, which continue to expose the athlete to high levels of stress or the cervical spine. Ten patients that fall into that category were treated over that time period (8 professional football players and 2 professional race car drivers). Both drivers were treated in the off season and returned to driving within 4 weeks. The football players form a more heterogeneous group with differing levels of preoperative deficits. Seven players returned to play at full capacity once preoperative motor deficits had cleared. One of these players with multilevel spondylotic disease required additional surgery 1½ years postoperatively and retired from competition. The one athlete who never returned to playing sustained a game-related complete C5 deficit secondary to spondylotic foramenal stenosis. His motor deficit never improved enough to return to full capacity.
Conclusions The posterior CELF has proven itself as a safe and effective surgical treatment for unilateral cervical radiculopathy in the general patient population. It has provided good relief of radiculopathy pain and deficits and minimized postoperative recovery times without altering the cervical motion segments, thereby eliminating increased strain on adjacent levels. These same features have made the procedure very attractive to competitive athletes, especially those for whom it is a profession. In many ways, they are the ideal patient with their motivation to recover and resume training. The extraordinary stresses of some sports such as football and car racing have been generally well tolerated once back to full capacity.
Although the CELF procedure can be challenging to master, it provides many advantages for the athlete in general.
Acknowledgments The author would like to thank Christine Renda for her assistance in preparation of the manuscript.
References 1. Frykholm R: Cervical root compression resulting from disc degeneration and root sleeve fibrosis. Acta Chir Scand 160:1-149, 1951 2. Semmes RE, Murphy F: Syndrome of unilateral rupture of the sixth cervical intervertebral disc, with compression of the seventh cervical nerve root. Report of four cases with symptoms simulating coronary disease. JAMA 121:1209-1214, 1943 3. Zeidman SM, Ducker TB: Posterior cervical laminoforaminotomy for radiculopathy: Review of 172 cases. Neurosurgery 33:356-362, 1993 4. Williams RW: Microcervical foraminotomy. A surgical alternative for intractable radicular pain. Spine 8:708-716, 1983 5. Baba G. Furusawa N, Imura S, et al: Late radiographic findings after anterior cervical fusion for spondylotic myeloradiculopathy. Spine 18: 2167-2173, 1993 6. Robinson RA, Smith GW: Anterolateral cervical disc removal and interbody fusion for cervical disc syndrome. Bull John Hopkins Hospital 96:223, 1955 7. Cloward R: The anterior approach for removal of ruptured cervical discs. J Neurosurg 15:602-617, 1958 8. DePalma AF, Rothman RH, Lewinnek GE, et al: Anterior interbody fusion for severe cervical disc degeneration. Surg Gynecol Obstet 134: 755-758, 1972 9. Pospiech J, Stolke D, Wilke HJ, et al: Intradiscal pressure recordings in the cervical spine. Neurosurgery 44:379-385, 1999 10. Hilibrand AS, Yoo JU, Carlson GD, et al: The success of anterior cervical arthrodesis adjacent to a previous fusion. Spine 22:1574-1579, 1997 11. Flynn TB: Neurological complication of anterior cervical interbody fusion. Spine 7:536-539, 1982 12. Simeone F, Dillin W: Treatment of cervical disc disease: selection of operative approach. Contemp Neurosurg 8:1-6, 1986 13. Smith M, Foley K: Microendoscopic discectomy. Tech Neurosurg 3:301-307, 1997 14. Adamson T: Microendoscopic posterior cervical laminoforaminotomy for unilateral radiculopathy: results of a new technique in 100 cases. J Neurosurg Spine 95:51-57, 2001 15. Adamson, T: The impact of minimally invasive cervical spine surgery. J Neurosurg Spine 1:43-46, 2004