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A decade of experience with expansile laminoplasty: lessons learned
A Decade of Experience with Expansile Laminoplasty: Lessons Learned Frank Feigenbaum, MD and Fraser C. Henderson, MD
E
xpansile, or “open door,” laminoplasty is a valuable surgical technique for treating multilevel cervical spinal canal stenosis, particularly in the setting of ossification of the posterior longitudinal ligament (Fig 1). Originally described by Hirabayshi et al in 1983,1 the procedure is intended to maximize spinal canal decompression while preserving stability and range of motion. In contrast to potentially destabilizing standard posterior cervical decompression, the lamina and spinous processes are modified to relieve spinal cord compression, but left intact to continue their role in structural stability. Unlike typical multilevel anterior cervical procedures, the posterior exposure used for expansile laminoplasty provides easy access to pathology at multiple spinal levels with less struggle and cosmetic impact. The probability of dural tearing is dramatically reduced, particularly when compared with anterior corpectomy in the setting of ossification of the posterior longitudinal ligament. Additionally, fusion across multiple spinal levels is avoided, thereby preserving intersegmental mobility and avoiding the risk of anterior nonunion. As with other surgical procedures, however, knowing when to apply the technique is critical for success.
Patient Selection Most patients with cervical stenosis typically suffer from the gradual onset of myelopathic symptoms such as numbness, weakness, spasticity, decreased walking endurance, bowel and bladder difficulties, and sexual dysfunction. Among these, decreased walking endurance and seemingly nonFrom the Research Medical Center, Kansas City, Missouri, and The Department of Neurosurgery, Georgetown University Medical Center, Washington, DC Address reprint requests to F. Feigenbaum, 6420 Prospect, Ste T411, Research Medical Center, Kansas City, Missouri 64132. E-mail: [email protected] © 2004 Elsevier Inc. All rights reserved. 1040-7383/04/1601-0008$30.00/0 doi:10.1053/j.semss.2004.04.008
56
dermatomal extremity sensory changes are often the earliest to appear. Bladder dysfunction, ie, nocturia and urgency, also tends to develop early, but is often dismissed by patients who attribute it to everything from normal aging to prostatic hypertrophy. Conversely, patients with advanced cervical stenosis can be severely disabled due to prolonged spinal cord compression. Such patients often suffer from extensive muscle atrophy, sensory loss, and spasticity. In its most advanced form, patients are completely debilitated and wheelchair bound or bedridden. In some instances, cervical stenosis can produce a sudden and dramatic onset of symptoms. This subset of patients is typified by the individual who develops central cord syndrome after head or neck trauma. Not uncommonly, previously asymptomatic patients develop serious impairment after a whiplash (hyperflexion-hyperextension) injury or a fall resulting in a blow to the forehead. The underlying stenosis becomes apparent only after high-resolution imaging of the cervical spine is obtained. Over the years, it has been our experience that a significant number of expansile laminoplasty procedures also include one or more foramenotomies. This is most likely due to the fact that cervical stenosis is often accompanied by foramenal stenosis. Such patients therefore suffer from both myelopathic symptoms and radiculopathy. Interestingly, patients seem more likely to seek medical attention for relief of radicular symptoms than for myelopathy, even when the latter is quite advanced. This is likely due to the more rapid onset and overall inconvenience of radicular symptoms. In contrast, the onset of myelopathic symptoms is typically gradual and more easily endured. A careful history and neurological examination will usually elicit the signs and symptoms of myelopathy. Conversely, an evaluation that focuses only on a patient’s radicular symptoms may overlook evidence of myelopathy. Additionally, myelopathic symptoms are often obscured by or attributed to the presence of conditions such as
Seminars in Spine Surgery, Vol 16, No 1 (March), 2004: pp 56-60
Experience with Expansile Laminoplasty
57
Figure 1. (a) Noncontrast CT scan demonstrating ossification of the posterior longitudinal ligament with spinal canal encroachment. (b) Multilevel cervical stenosis with ossification of the posterior longitudinal ligament as seen on T2-weighted sagittal MRI.
rheumatoid arthritis, diabetes, and prostate problems. For example, myelopathic urinary frequency and nocturia may be attributed to prostatism or diabetic autonomic neuropathy; neck pain and hand weakness may be attributed to “old age,” and sensory loss in the hands is frequently misdiagnosed as carpal tunnel syndrome or ulnar neuropathy. Some symptoms of myelopathy often go unrecognized, such as numbness of the neck and face (Dejerene’s sign), wasting of the intrinsic muscles of the hand, and loss of manual dexterity. The latter can be elicited by questioning the patient about typing errors, difficulty with buttons or zippers, and problems gripping heavy objects. Also commonly unrecognized is the relationship between cervical myelopathy and low back or leg symptoms. Cervical myelopathy can produce seemingly unrelated paresthesias of the feet, nondermatomal leg pain, claudication, and leg spasms. The diagnosis is frequently made difficult by the coexistence of lumbar stenosis.
Radiographic Assessment An MRI or CT myelogram is usually sufficient for preoperative surgical planning. Axial images
most accurately reflect the extent of spinal canal stenosis. However, MRI may give a false impression by underestimating the degree of stenosis. A bright signal on T2-wieghted images may make a small rim of cerebrospinal fluid appear larger than it is in reality. Consequently, this may give the illusion that stenosis is not significant. CT myelography can also be misleading if axial imaging is not obtained in a plane perpendicular to the spinal cord since tangential axial imaging exaggerates the width of the spinal cord and the cerebrospinal fluid that surrounds it. We typically reserve CT myelography for patients with complex degenerative changes in whom it is not possible to obtain a satisfactory MRI. In our experience, the cervical spinal levels most commonly requiring treatment are C3 to C7. However, we have found that canal stenosis at C7 is usually limited to the upper margin of the lamina and is treatable with laminotomy instead of expansile laminoplasty. On occasion, the same is also applicable for the lower margin of C2. Cervical spine alignment should be assessed on preoperative images. Treatment with expansile laminoplasty is reserved for patients in whom
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cervical lordosis is preserved. The presence of kyphosis or subluxation should militate against laminoplasty and prompt the surgeon to consider simple laminectomy supplemented with lateral mass plating and fusion. The presence of a large disc herniation argues for anterior discectomy due to the risk of spinal cord injury during prone positioning. We find it beneficial to review imaging studies with the patient. Most patients are able to appreciate the extent to which their spinal cord appears compressed after a brief description of the anatomy. This seems to help them better understand the nature of their predicament and makes the recommendation for surgery more palatable. Patients with whom we have reviewed films also require less time and explanation to grasp the technical concept behind expansile laminoplasty.
Surgical Technique Positioning and Exposure After application of headpins, the patient is turned to the prone position on chest rolls. The surgeon maintains control of the head during turning and positioning. The operating table is placed in reverse Trendelenberg to provide a level aspect to the back of the neck. The patient’s head is then tucked into a military position (extended at the cervico-thoracic junction and flexed at the cranio-cervical junction). A width of at least three fingerbreadths should pass between the patient’s mandible and sternum, and the chin should be well clear of the end of the table. The arms are tucked at the patient’s sides. We typically retract the shoulders with wide cloth tape secured to the contralateral end of the table to give better exposure to the neck. This latter maneuver is particularly useful in large patients, but care should be taken not to over-retract the shoulders for fear of producing a traction injury to the brachial plexus. A lateral cervical image is obtained to confirm good spinal alignment after positioning is complete. A wide, bilateral subperiostial exposure of the desired laminae is performed. Care is taken to preserve the interspinous tissues. We expose a portion of the adjacent lamina above and below the treatment area for optimal visualization and access. For example, the lower half of C2 and the upper half of C7 are exposed if expansile laminoplasty from C3 to C6 is planned.
If indicated, keyhole foramenotomies are performed before laminoplasty since foramenal bone work is safer in the presence of intact posterior elements. Also, foramenotomy sites may be obscured significantly if laminoplasty is performed first. Additionally, determining the depth to the dura during foramenotomy can greatly assist the surgeon later during laminar transection. The Leksell rongeur is then used to harvest small pieces of bone from the tips of the exposed spinous processes for later grafting. We typically obtain a 5-mm fragment of spinous process tip for each lamina to be expanded and thoroughly clean the graft of any soft tissue.
Laminar Expansion The surgeon then creates a unilateral cut through the lamina 1 cm lateral to the midline with a high-speed drill using an M-8 equivalent drill bit. We typically make the laminar cut on the patient’s most symptomatic side, though this is probably more a matter of surgeon preference. Care is taken to produce a narrow laminar cut since overdrilling the lamina may restrict the space available for miniplate screw fixation later on. The assistant is relied on to irrigate and suction while the surgeon maintains maximum two-handed control on the drill. Care should be taken to completely transect the lamina longitudinally, but not to disturb the underlying dura. A rectangular strip of gel foam can be placed in the trough after drilling if bleeding is encountered from the cut bone edges. After unilateral laminar transection is complete, the drill is then used to create a halfthickness cut, or score, in the contralateral lamina. The depth of the score is such that it becomes amenable to “green-stick” fracture. It is important to avoid complete transection of the lamina by overdrilling. If this should inadvertently occur, the floating lamina can be removed and secured back into position with a short miniplate segment and screws. The laminae are now ready to be “expanded.” The double-toothed tine of a Kocher hemostat is positioned securely under the medial edge of the transected lamina. The other end of the Kocher is placed on the contralateral, or scored, lamina of the same level. The Kocher is then rotated to create a “green-stick” fracture on the scored side of the lamina. If the lamina resists being ex-
Experience with Expansile Laminoplasty
59
Laminar Fusion
Figure 2. Three graft/plate options for expansile laminoplasty are shown. From right to left, 6-, 8-, and 10-millimeter prebent titanium plates are demonstrated. On the right, a spinous process tip autograft has been interposed between the cut laminar edges. Commercially available allograft spacers (Synthes™) are also shown. At far left, an 8-millimeter parallel edge spacer is interposed. In the middle, a 6-millimeter angled edge spacer is seen. (Color version of figure is available online.)
panded, the surgeon should confirm complete longitudinal laminar transection on the side of the trough. Alternatively, deeper scoring of the contralateral lamina may be what is required. During laminar expansion, the surgeon’s attention is naturally focused on side of the widening laminar opening. However, a moment should be taken to confirm that the Kocher tine on the contralateral, or scored, lamina is centered well and not in a position where it may slip medially into the dura. The lamina should be held securely with the Kocher hemostat to prevent the lamina from slipping out and springing downward onto the thecal sac. Once expanded, the lamina is secured with a miniplate and screws. We prefer a 2.0-mm titanium plating system with a six-hole plate bent into the shape of a “Z.” Prebent expansile laminoplasty plates and notched bone grafts are also commercially available (Synthes™). The plate should be positioned across the laminar opening such that two 6-millimeter screws can be placed in the lamina, and one or two 8-millimeter screws can be placed in the pars interarticularis. A trustworthy assistant can facilitate the process by holding the expanded lamina with the Kocher hemostat while the surgeon places the miniplate and screws.
We employ two main fusion techniques after laminar expansion. Most commonly, we utilize an on-lay technique by placing a harvested spinous process tip under each miniplate between the cut edges of the transected lamina (Fig 2). The bone graft should not significantly depress the underlying dura. This is followed by laying demineralized bone-matrix putty over the graft and miniplate from lamina to pars interarticularis. A second option is to perform a graft interposition. Although rib or iliac crest autograft can be harvested for this purpose, we prefer commercially available precut grafts (Synthes™) that can be inserted between the cut edges of the lamina (Fig 2). This technique differs from the on-lay approach in that the precut graft is interposed in the laminar opening before miniplate placement. This technique carries a greater expense and is slightly more time consuming, but offers several advantages. Since the interposed graft functions to hold the lamina in the expanded position, the assistant’s hands are free during miniplate fixation. Since the graft is under compression, we believe it to have a higher likelihood of successfully fusing. Additionally, we have found that a superior postoperative radiographic appearance is achieved (Fig 3).
Figure 3. Postoperative axial CT myelogram image demonstrating expansile laminoplasty using a commercially available precut fibular graft (Synthes™). The graft is seen interposed between the cut laminar edges. A titanium miniplate overlies the graft. One of the screws used to secure the plate is seen inserted onto the distal lamina.
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The wound is closed in several layers over a subfascial drain, which is typically removed on the first postoperative day. We have patients wear a neck brace for 1 month to promote healing with good cervical posture.
Patient Satisfaction In our experience, patients benefit most from expansile laminoplasty when treated relatively soon after the onset of myelopathic symptoms. That is not to say that patients with advanced myelopathy do not experience improvement. Rather, we have found that reversal of symptoms is most complete when treated early, and that surgery in patients with advanced myelopathy serves more to prevent disease progression. Patients should be educated on this point preoperatively so as not to encourage unrealistic expectations regarding the surgery. In general,
patients are able to grasp the concept of spinal cord injury due to chronic compression and understand that some spinal cord damage is not reversible. Additionally, relief of radicular symptoms seems to be a critical factor for patient satisfaction. It is therefore essential for the surgeon to accurately diagnose and treat symptomatic foramenal stenosis at the time of expansile laminoplasty. Failure to do so invariably results in persistent radicular symptoms and a perception on the part of the patient that surgery has failed, regardless of the improvement in their myelopathy.
References 1. Hirabayshi K, Watanabe K, Wakano K, et al: Expansive open-door laminoplasty for cervical stenotic myelopathy. Spine 8:693-699, 1983
E
xpansile, or “open door,” laminoplasty is a valuable surgical technique for treating multilevel cervical spinal canal stenosis, particularly in the setting of ossification of the posterior longitudinal ligament (Fig 1). Originally described by Hirabayshi et al in 1983,1 the procedure is intended to maximize spinal canal decompression while preserving stability and range of motion. In contrast to potentially destabilizing standard posterior cervical decompression, the lamina and spinous processes are modified to relieve spinal cord compression, but left intact to continue their role in structural stability. Unlike typical multilevel anterior cervical procedures, the posterior exposure used for expansile laminoplasty provides easy access to pathology at multiple spinal levels with less struggle and cosmetic impact. The probability of dural tearing is dramatically reduced, particularly when compared with anterior corpectomy in the setting of ossification of the posterior longitudinal ligament. Additionally, fusion across multiple spinal levels is avoided, thereby preserving intersegmental mobility and avoiding the risk of anterior nonunion. As with other surgical procedures, however, knowing when to apply the technique is critical for success.
Patient Selection Most patients with cervical stenosis typically suffer from the gradual onset of myelopathic symptoms such as numbness, weakness, spasticity, decreased walking endurance, bowel and bladder difficulties, and sexual dysfunction. Among these, decreased walking endurance and seemingly nonFrom the Research Medical Center, Kansas City, Missouri, and The Department of Neurosurgery, Georgetown University Medical Center, Washington, DC Address reprint requests to F. Feigenbaum, 6420 Prospect, Ste T411, Research Medical Center, Kansas City, Missouri 64132. E-mail: [email protected] © 2004 Elsevier Inc. All rights reserved. 1040-7383/04/1601-0008$30.00/0 doi:10.1053/j.semss.2004.04.008
56
dermatomal extremity sensory changes are often the earliest to appear. Bladder dysfunction, ie, nocturia and urgency, also tends to develop early, but is often dismissed by patients who attribute it to everything from normal aging to prostatic hypertrophy. Conversely, patients with advanced cervical stenosis can be severely disabled due to prolonged spinal cord compression. Such patients often suffer from extensive muscle atrophy, sensory loss, and spasticity. In its most advanced form, patients are completely debilitated and wheelchair bound or bedridden. In some instances, cervical stenosis can produce a sudden and dramatic onset of symptoms. This subset of patients is typified by the individual who develops central cord syndrome after head or neck trauma. Not uncommonly, previously asymptomatic patients develop serious impairment after a whiplash (hyperflexion-hyperextension) injury or a fall resulting in a blow to the forehead. The underlying stenosis becomes apparent only after high-resolution imaging of the cervical spine is obtained. Over the years, it has been our experience that a significant number of expansile laminoplasty procedures also include one or more foramenotomies. This is most likely due to the fact that cervical stenosis is often accompanied by foramenal stenosis. Such patients therefore suffer from both myelopathic symptoms and radiculopathy. Interestingly, patients seem more likely to seek medical attention for relief of radicular symptoms than for myelopathy, even when the latter is quite advanced. This is likely due to the more rapid onset and overall inconvenience of radicular symptoms. In contrast, the onset of myelopathic symptoms is typically gradual and more easily endured. A careful history and neurological examination will usually elicit the signs and symptoms of myelopathy. Conversely, an evaluation that focuses only on a patient’s radicular symptoms may overlook evidence of myelopathy. Additionally, myelopathic symptoms are often obscured by or attributed to the presence of conditions such as
Seminars in Spine Surgery, Vol 16, No 1 (March), 2004: pp 56-60
Experience with Expansile Laminoplasty
57
Figure 1. (a) Noncontrast CT scan demonstrating ossification of the posterior longitudinal ligament with spinal canal encroachment. (b) Multilevel cervical stenosis with ossification of the posterior longitudinal ligament as seen on T2-weighted sagittal MRI.
rheumatoid arthritis, diabetes, and prostate problems. For example, myelopathic urinary frequency and nocturia may be attributed to prostatism or diabetic autonomic neuropathy; neck pain and hand weakness may be attributed to “old age,” and sensory loss in the hands is frequently misdiagnosed as carpal tunnel syndrome or ulnar neuropathy. Some symptoms of myelopathy often go unrecognized, such as numbness of the neck and face (Dejerene’s sign), wasting of the intrinsic muscles of the hand, and loss of manual dexterity. The latter can be elicited by questioning the patient about typing errors, difficulty with buttons or zippers, and problems gripping heavy objects. Also commonly unrecognized is the relationship between cervical myelopathy and low back or leg symptoms. Cervical myelopathy can produce seemingly unrelated paresthesias of the feet, nondermatomal leg pain, claudication, and leg spasms. The diagnosis is frequently made difficult by the coexistence of lumbar stenosis.
Radiographic Assessment An MRI or CT myelogram is usually sufficient for preoperative surgical planning. Axial images
most accurately reflect the extent of spinal canal stenosis. However, MRI may give a false impression by underestimating the degree of stenosis. A bright signal on T2-wieghted images may make a small rim of cerebrospinal fluid appear larger than it is in reality. Consequently, this may give the illusion that stenosis is not significant. CT myelography can also be misleading if axial imaging is not obtained in a plane perpendicular to the spinal cord since tangential axial imaging exaggerates the width of the spinal cord and the cerebrospinal fluid that surrounds it. We typically reserve CT myelography for patients with complex degenerative changes in whom it is not possible to obtain a satisfactory MRI. In our experience, the cervical spinal levels most commonly requiring treatment are C3 to C7. However, we have found that canal stenosis at C7 is usually limited to the upper margin of the lamina and is treatable with laminotomy instead of expansile laminoplasty. On occasion, the same is also applicable for the lower margin of C2. Cervical spine alignment should be assessed on preoperative images. Treatment with expansile laminoplasty is reserved for patients in whom
58
Feigenbaum and Henderson
cervical lordosis is preserved. The presence of kyphosis or subluxation should militate against laminoplasty and prompt the surgeon to consider simple laminectomy supplemented with lateral mass plating and fusion. The presence of a large disc herniation argues for anterior discectomy due to the risk of spinal cord injury during prone positioning. We find it beneficial to review imaging studies with the patient. Most patients are able to appreciate the extent to which their spinal cord appears compressed after a brief description of the anatomy. This seems to help them better understand the nature of their predicament and makes the recommendation for surgery more palatable. Patients with whom we have reviewed films also require less time and explanation to grasp the technical concept behind expansile laminoplasty.
Surgical Technique Positioning and Exposure After application of headpins, the patient is turned to the prone position on chest rolls. The surgeon maintains control of the head during turning and positioning. The operating table is placed in reverse Trendelenberg to provide a level aspect to the back of the neck. The patient’s head is then tucked into a military position (extended at the cervico-thoracic junction and flexed at the cranio-cervical junction). A width of at least three fingerbreadths should pass between the patient’s mandible and sternum, and the chin should be well clear of the end of the table. The arms are tucked at the patient’s sides. We typically retract the shoulders with wide cloth tape secured to the contralateral end of the table to give better exposure to the neck. This latter maneuver is particularly useful in large patients, but care should be taken not to over-retract the shoulders for fear of producing a traction injury to the brachial plexus. A lateral cervical image is obtained to confirm good spinal alignment after positioning is complete. A wide, bilateral subperiostial exposure of the desired laminae is performed. Care is taken to preserve the interspinous tissues. We expose a portion of the adjacent lamina above and below the treatment area for optimal visualization and access. For example, the lower half of C2 and the upper half of C7 are exposed if expansile laminoplasty from C3 to C6 is planned.
If indicated, keyhole foramenotomies are performed before laminoplasty since foramenal bone work is safer in the presence of intact posterior elements. Also, foramenotomy sites may be obscured significantly if laminoplasty is performed first. Additionally, determining the depth to the dura during foramenotomy can greatly assist the surgeon later during laminar transection. The Leksell rongeur is then used to harvest small pieces of bone from the tips of the exposed spinous processes for later grafting. We typically obtain a 5-mm fragment of spinous process tip for each lamina to be expanded and thoroughly clean the graft of any soft tissue.
Laminar Expansion The surgeon then creates a unilateral cut through the lamina 1 cm lateral to the midline with a high-speed drill using an M-8 equivalent drill bit. We typically make the laminar cut on the patient’s most symptomatic side, though this is probably more a matter of surgeon preference. Care is taken to produce a narrow laminar cut since overdrilling the lamina may restrict the space available for miniplate screw fixation later on. The assistant is relied on to irrigate and suction while the surgeon maintains maximum two-handed control on the drill. Care should be taken to completely transect the lamina longitudinally, but not to disturb the underlying dura. A rectangular strip of gel foam can be placed in the trough after drilling if bleeding is encountered from the cut bone edges. After unilateral laminar transection is complete, the drill is then used to create a halfthickness cut, or score, in the contralateral lamina. The depth of the score is such that it becomes amenable to “green-stick” fracture. It is important to avoid complete transection of the lamina by overdrilling. If this should inadvertently occur, the floating lamina can be removed and secured back into position with a short miniplate segment and screws. The laminae are now ready to be “expanded.” The double-toothed tine of a Kocher hemostat is positioned securely under the medial edge of the transected lamina. The other end of the Kocher is placed on the contralateral, or scored, lamina of the same level. The Kocher is then rotated to create a “green-stick” fracture on the scored side of the lamina. If the lamina resists being ex-
Experience with Expansile Laminoplasty
59
Laminar Fusion
Figure 2. Three graft/plate options for expansile laminoplasty are shown. From right to left, 6-, 8-, and 10-millimeter prebent titanium plates are demonstrated. On the right, a spinous process tip autograft has been interposed between the cut laminar edges. Commercially available allograft spacers (Synthes™) are also shown. At far left, an 8-millimeter parallel edge spacer is interposed. In the middle, a 6-millimeter angled edge spacer is seen. (Color version of figure is available online.)
panded, the surgeon should confirm complete longitudinal laminar transection on the side of the trough. Alternatively, deeper scoring of the contralateral lamina may be what is required. During laminar expansion, the surgeon’s attention is naturally focused on side of the widening laminar opening. However, a moment should be taken to confirm that the Kocher tine on the contralateral, or scored, lamina is centered well and not in a position where it may slip medially into the dura. The lamina should be held securely with the Kocher hemostat to prevent the lamina from slipping out and springing downward onto the thecal sac. Once expanded, the lamina is secured with a miniplate and screws. We prefer a 2.0-mm titanium plating system with a six-hole plate bent into the shape of a “Z.” Prebent expansile laminoplasty plates and notched bone grafts are also commercially available (Synthes™). The plate should be positioned across the laminar opening such that two 6-millimeter screws can be placed in the lamina, and one or two 8-millimeter screws can be placed in the pars interarticularis. A trustworthy assistant can facilitate the process by holding the expanded lamina with the Kocher hemostat while the surgeon places the miniplate and screws.
We employ two main fusion techniques after laminar expansion. Most commonly, we utilize an on-lay technique by placing a harvested spinous process tip under each miniplate between the cut edges of the transected lamina (Fig 2). The bone graft should not significantly depress the underlying dura. This is followed by laying demineralized bone-matrix putty over the graft and miniplate from lamina to pars interarticularis. A second option is to perform a graft interposition. Although rib or iliac crest autograft can be harvested for this purpose, we prefer commercially available precut grafts (Synthes™) that can be inserted between the cut edges of the lamina (Fig 2). This technique differs from the on-lay approach in that the precut graft is interposed in the laminar opening before miniplate placement. This technique carries a greater expense and is slightly more time consuming, but offers several advantages. Since the interposed graft functions to hold the lamina in the expanded position, the assistant’s hands are free during miniplate fixation. Since the graft is under compression, we believe it to have a higher likelihood of successfully fusing. Additionally, we have found that a superior postoperative radiographic appearance is achieved (Fig 3).
Figure 3. Postoperative axial CT myelogram image demonstrating expansile laminoplasty using a commercially available precut fibular graft (Synthes™). The graft is seen interposed between the cut laminar edges. A titanium miniplate overlies the graft. One of the screws used to secure the plate is seen inserted onto the distal lamina.
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Feigenbaum and Henderson
The wound is closed in several layers over a subfascial drain, which is typically removed on the first postoperative day. We have patients wear a neck brace for 1 month to promote healing with good cervical posture.
Patient Satisfaction In our experience, patients benefit most from expansile laminoplasty when treated relatively soon after the onset of myelopathic symptoms. That is not to say that patients with advanced myelopathy do not experience improvement. Rather, we have found that reversal of symptoms is most complete when treated early, and that surgery in patients with advanced myelopathy serves more to prevent disease progression. Patients should be educated on this point preoperatively so as not to encourage unrealistic expectations regarding the surgery. In general,
patients are able to grasp the concept of spinal cord injury due to chronic compression and understand that some spinal cord damage is not reversible. Additionally, relief of radicular symptoms seems to be a critical factor for patient satisfaction. It is therefore essential for the surgeon to accurately diagnose and treat symptomatic foramenal stenosis at the time of expansile laminoplasty. Failure to do so invariably results in persistent radicular symptoms and a perception on the part of the patient that surgery has failed, regardless of the improvement in their myelopathy.
References 1. Hirabayshi K, Watanabe K, Wakano K, et al: Expansive open-door laminoplasty for cervical stenotic myelopathy. Spine 8:693-699, 1983