Acta Neurochir (2014) 156:1225–1230 DOI 10.1007/s00701-014-2078-9
HOW I DO IT - SPINE
Modified open-door laminoplasty for the surgical treatment of cervical spondylotic myelopathy in elderly patients Stefan Alexander König & Uwe Spetzger
Received: 14 January 2014 / Accepted: 19 March 2014 / Published online: 16 April 2014 # Springer-Verlag Wien 2014
Abstract Background The authors describe their experience with a modified version of the standard technique of open-door laminoplasty for the surgical treatment of spondylotic myelopathy in elderly patients with temporary removal of the laminae, extensive decompression, and pre-plating of the laminae beyond the surgical field. Methods Description of surgical anatomy, surgical technique, indications, limitations, complications, and specific perioperative considerations, as well as specific information to give to the patient about surgery and potential risks. A summary of ten key points is given. Conclusions Transection of the laminae on both sides (temporary laminectomy) and pre-plating of the laminae outside of the surgical field has several advantages: better decompression of the spinal canal and the neuroforamina on both sides, easier undercutting of adjacent vertebral arches for craniocaudal decompression, and no risk of spinal cord injury by the screwdriver when attaching plates to the laminae.
craniotome close to the lateral mass on one side. On the other side only the outer layer of compact bone is cut. Usually, laminoplasty involves three laminae. When the block of laminae with their ligaments and spinous processes (the “door”) is opened, this procedure leads to a greenstick fracture of the lateral laminae on the side with the incomplete transection of bone. The bone gutter on the other side is fixed with titanium mini-plates after opening the “door”. The authors prefer a modified technique with transection of the lateral laminae on both sides (Fig. 1b) and a temporary removal of all posterior osseoligamentous structures (Fig. 1c) for a more effective and safer decompression as well as a preplating of the laminae beyond the surgical field (see: Description of the technique). Beside the open-door technique, some institutions use the so-called French-door technique with a splitting of the spinous processes and laminae in the midline [1], but Lee at al. [2] could show that the open-door technique leads to better clinical and radiological results.
Keywords Cervical spondylotic myelopathy . Modified laminoplasty . Surgical technique
Description of the technique
Relevant surgical anatomy The classical technique of open-door laminoplasty for the surgical treatment of cervical spondylotic myelopathy (CSM) includes a transection of the lateral laminae with a Electronic supplementary material The online version of this article (doi:10.1007/s00701-014-2078-9) contains supplementary material, which is available to authorized users. S. A. König (*) : U. Spetzger Neurochirurgische Klinik, Klinikum Karlsruhe, Moltkestr. 90, 76133 Karlsruhe, Germany e-mail: [email protected]
A posterior cervical midline approach is used to expose the lateral masses and the laminae of the involved vertebrae. The patient positioning includes prone position with fixing of the head in a Mayfield clamp in moderate flexion position (‘Concorde position´). The skin incision depends on the number and height of levels being involved as well as on the thickness of the muscles, but usually extends from the external occipital protuberance to the spinous process of T1. The cervical fascia is cut as far medial as possible, right on the edges of the spinous processes on both sides. The insertions of the trapezius muscles, the spinalis muscles, the semispinalis capitis muscles, and the multifidus cervicis muscles are sharply dissected from the spinous processes of the involved
1226
Acta Neurochir (2014) 156:1225–1230
Fig. 1 Surgical steps of posterior decompression and laminoplasty: Creation of a circumscript laminotomy with a diamond drill as an entry point for the craniotome (a). Lamintomy of C5, C6, and C7 with a craniotome (b). Removal of the three laminae in one piece (c). Completing decompression of the spinal chord with a Kerrison punch (d). Finished decompression (e). Replantation of the C7 arch and plate fixation on the short side of the open-door laminoplasty (f). Plate fixation of the C6 arch on the open side of the laminoplasty (g). Finished open-door laminoplasty C5 to C7 (h)
vertebrae. If the spinal stenosis is located in the upper cervical spine, it is also necessary to sharply dissect the rectus capitis posterior muscles and the obliquus capitis inferior muscles from the spinous process of C2. After placing a self-retaining retractor, the lateral masses have to be exposed to have enough space for placing the titanium mini-plates. At the cranial edge of the most cranial vertebral arch, the interlaminar space is enlarged with a 4-millimeter diamond drill (Fig. 1a). The right position for these small entry burr holes is the transition of the lamina to the lateral mass. There is no specific landmark for surgical orientation, but the use of a small diamond drill is helpful to do corrections if the surgeon is far too lateral (cancellous bone of the lateral mass will appear). Afterwards, remnants of the ligamentum flavum are removed with a Kerrison punch to gain enough space for the footplate of the craniotome. The craniotome is used to cut the
lateral laminae near the lateral masses to make sure that the transection is as far lateral as possible (Fig. 1b). The same procedure is repeated on the contralateral side. Afterwards, the laminae (usually three) can be removed en bloc, including the ligaments and spinous processes (Fig. 1c). Now there is enough space for hemostasis of bleeding from epidural veins. Afterwards, the decompression of the spinal cord can be extended cranially and caudally by undercutting the laminae of the adjacent vertebrae (Fig. 1d). In cases of additional foraminal stenosis, it is possible to decompress the cervical nerve roots as well (Fig. 1e). The next step is a complete removal of the ligamenta flava at the inner side of the temporarily removed vertebral arches. That leads to an additional improvement of the sagittal diameter of the spinal canal. When using the classical open-door technique, this step of the operation is much more difficult because there is very little space
Acta Neurochir (2014) 156:1225–1230
1227
for the Kerrison punch, and the risk of spinal cord injury is much higher. Before the laminae are placed back in the surgical field, they are pre-plated with two straight 20-millimeter titanium mini-plates on the side of the gutter and shorter 15-millimeter X-plates on the other side. The screws are self-drilling 4millimeter standard screws. After placing the laminae back into the surgical field, the authors start with fixing the shorter plates to the lateral mass (Fig. 1f), and then the longer plates at the side of the gutter are attached (Fig. 1g), because the adjustment of the width of the gutter is much easier that way. After fixing all laminae on both sides, the open-door laminoplasty is completed (Fig. 1h). The closure includes the placement of a wound drain and sutures of the muscle insertions in the midline to achieve physiological conditions. The whole procedure is shown in the accompanying video.
Indications Symptomatic CSM usually requires surgical therapy. The degenerative process mainly leads to anterior spinal cord compression; thus, an anterior approach is indicated in most cases. If the space-occupying lesion comes from the posterior aspect of the spinal canal, then, of course, the posterior approach should be preferred. Beyond that, elderly patients ≥ 75 years of age are in an exceptional position because the risk for surgical complications related to the anterior approach is higher [3, 4]. Furthermore, these patients show spontaneous bony fusion of cervical vertebral bodies; thus, it would be necessary to drill through the whole intervertebral space or to do a corpectomy when using an anterior approach. In those cases, a posterior approach might be a better choice, even if there is anterior compression of the spinal cord by ligaments and osteophytes (Fig. 2). The posterior approach requires a lordotic or at least a straight configuration of the cervical spine to get enough space for the spinal cord when doing a laminoplasty or laminectomy and fusion [3]. The latter procedure has a higher risk of implant failure in elderly patients due to the high incidence of osteoporosis in that age group. Thus, open-door laminoplasty is a frequent procedure for posterior decompression in elderly patients. Another advantage of laminoplasty compared to laminectomy and fusion is the fact that the range of motion of the cervical spine is less decreased after the procedure. In the authors´ institution, posterior decompression is done by laminectomy and fusion or laminoplasty. Nevertheless, some authors also consider laminectomy without fusion, since there is no statistical proof that laminoplasty is superior to laminectomy without fusion [5]. Thus, cervical laminectomy can be an option for very old patients, with a small number of levels being involved in the cervical spinal stenosis.
Fig. 2 An 81-year-old male patient with CSM. Spinal cord compression resulted from anterior and posterior spondylosis, sagittal MR image (a). An incomplete spontaneous fusion of the C5, C6, and C7 vertebral bodies was detected in the sagittal reconstruction of a preoperative CT scan (b); therefore, posterior decompression was indicated. Narrowing of the spinal canal in the axial plane (c). Temporary removal of the C5, C6, and C7 arch allowed lateral decompression of the spinal cord that can be seen in the coronal reconstruction of a postoperative CT scan (d). Improvement of the spinal canal diameter in the sagittal plane (e; compare with b) and in the axial plane (f; compare with c)
Limitations The success of a posterior decompression is limited in patients with a kyphotic configuration of the cervical spine, because the spinal cord is unable to occupy the additional space from a laminoplasty or laminectomy [3]. In cases of good lordosis, it is possible to decompress the spinal cord even when there is a moderate anterior space-occupying lesion (Fig. 2). If disc herniation, hypertrophic ligaments or osteophytes occupy more than half of the sagittal diameter of the spinal canal, it is better to perform an anterior approach [6]. If the patient suffers from significant neck pain, a laminectomy and fusion are helpful due to the fixation of the facet joints.
1228
If there is secondary worsening of CSM after surgery, an imaging will be necessary. In most cases, the spinal cord cannot be visualized in magnetic resonance imaging (MRI) because of artifacts from the titanium plates. Thus, it might be necessary to do a myleogram and myelo computed tomography (CT).
How to avoid complications The modified technique with a temporary removal and preplating of the laminae outside of the surgical field helps to avoid complications. The risk of spinal cord injury during removal of ligamentum flavum at the inner side of the laminae is completely eliminated because the whole procedure is done outside of the surgical field. Furthermore, there is no risk of Fig. 3 Surgical treatment of a spinal stenosis from C2/3 to C3/4 (a, b). Open-door laminoplasty with the NewBridgeTM system (Blackstone Medical Inc., Springfield, MA, USA). Lateral (c) and anteroposterior (d) radiographs. Coronal (e) and axial (f) CT scan showing an insufficient widening of the spinal canal. Result after revision surgery with the use of the 1.5 Neuro Plating SystemTM (Biomet, Berlin, Germany): sagittal (g) and axial (h) CT scan showing a sufficient decompression of the spinal canal
Acta Neurochir (2014) 156:1225–1230
spinal cord injury by the screwdriver when attaching plates to the laminae.
Specific peri-operative considerations The standard postoperative workup is a CT scan of the cervical spine to document the widening of the spinal canal, as well as the correct position of all mini-plates and screws (Fig. 2d-f). The patient is usually discharged 7 to 10 days after surgery, mainly depending on severity of myelopathy and general condition (most patients are 75 years of age or older). The usual procedure after the hospital discharge is an inpatient rehabilitation treatment in a specific rehab clinic for three weeks. Physiotherapy mainly focuses on the neurological deficits of CSM: gait training, balance training, and
Acta Neurochir (2014) 156:1225–1230
occupational therapy to improve fine motor function of the hands. If CSM is stable or improved after surgery, the authors do not schedule specific follow-up examinations. If there is a secondary worsening of neurological deficits, the patient will be referred to our outpatient clinic by the patient´s neurologist or orthopedic specialist.
Specific information to give to the patient about surgery and potential risks The pre-operative prevalence of motor function impairment in the upper and lower extremities and that of sensory function impairment in the upper extremity is higher than that of other function impairments, whereas impairments in lower Fig. 4 Spinal stenosis from C4 to C7 with spondylotic myelopathy, sagittal MR scan (a). Postoperative result with widening of the spinal canal, sagittal MR scan (b). Anteroposterior radiograph (c) and axial CT scans (df) showing the titanium plates of the 1.5 Neuro Plating SystemTM (Biomet, Berlin, Germany). Beside the laminoplasty of C5 (d), C6 (e), and C7 (f) an undercutting of the C4 arch was performed. Broken mini-plate at C7 after a minor trauma one year after surgery, anteroposterior (g) and lateral (h) radiograph; axial CT scan. There were no clinical symptoms after the trauma, thus, therapy remained conservative
1229
extremity motor function and upper extremity sensory function often persist after surgery [7]. Nevertheless, a prospective study by Machino et al. verified adequate recovery from the symptoms of CSM in a population of elderly patients (age ≥ 75 years) after cervical laminoplasty [8]. The main features of patient information about potential risks of surgery are spinal cord injury, insufficient decompression (Fig. 3) and failure of the osteosynthesis (Fig. 4). Fehlings et al. analysed a population of 302 patients who underwent either an anterior-only, posterior-only or combined anteriorposterior procedures for the treatment of spondylotic myelopathy, and figured out an overall peri-operative complication rate of 15.6 % [9]. The most common complications were cardiopulmonary events (3.0 %), dysphagia (3.0 %), and superficial wound infection (2.3 %). Perioperative worsening of
1230
myelopathy was reported in 1.3 %. After a follow-up of two years there was a delayed complication rate of 4.4 %. Multivariate factors associated with an increased risk of complications included greater age, increased operative time, and the use of combined anterior procedures. Zhu et al. figured out a significantly higher re-operation rate for anterior surgery (8.57 %) compared to posterior surgery (0.3 %) in a meta-analysis that included eight studies [10]. The results of those studies are of importance for the preoperative information of the patient.
Summary 1) Temporary removal of the laminae (= temporary laminectomy) allows complete removal of flavum ligaments at the inner side of the vertebral arch for a more efficient decompression of the spinal cord. 2) Temporary removal of the laminae enables safe attachment of plates and screws—no risk of spinal cord injury. 3) Temporary removal of the laminae allows a better decompression of the lateral spinal canal and the nerve roots on both sides in cases of symptomatic radicular compression. 4) Temporary removal of the laminae allows a better undercutting of the adjacent superior and inferior vertebral arches in cases of stenosis at the level of the disc being adjacent to laminoplasty. 5) Temporary removal of the laminae enables a better hemostasis in the spinal canal on both sides compared to the standard technique. 6) Elderly patients have a significant higher risk of approach-related complications due to an anterior approach; thus, a posterior procedure is a better option. 7) Lordosis is a pre-condition for cervical laminoplasty. 8) Laminoplasty avoids hardware failure from posterior instrumentation, especially in cases of severe osteoporosis. 9) If there is a dominant side of the clinical myelopathy, then the open-side of the laminoplasty should be on the same side. 10) Use as many mini-plates as possible for the fixation of the laminae.
Acta Neurochir (2014) 156:1225–1230 Conflict of interest The authors certify that there is no actual or potential conflict of interest relating to this article.
References 1. Kim SW, Hai DM, Sundaram S, Kim YC, Park MS, Paik SH, Kwak YH, Kim TH (2013) Is cervical lordosis relevant in laminoplasty? Spine J 13(8):914–921 2. Lee DG, Lee SH, Park SJ, Kim ES, Chung SS, Lee CS, Eoh W (2013) Comparison of surgical outcomes after cervical laminoplasty: open-door technique versus French-door technique. J Spinal Disord Tech 26(6):E198–E203 3. Komotar RJ, Mocco J, Kaiser MG (2006) Surgical management of cervical myelopathy: indications and techniques for laminectomy and fusion. Spine J 6(6 Suppl):252S–267S 4. König SA, Ranguis S, Spetzger U (2013) Management of complex cervical instability. J Neurol Surg A Cent Eur Neurosurg. doi:10. 1055/s-0033-1345095 5. Ratliff JK, Cooper PR (2003) Cervical laminoplasty. A critical review. J Neurosurg 98(3 Suppl):230–238 6. Liu X, Min S, Zhang H, Zhou Z, Wang H, Jin A (2013) Anterior corpectomy versus posterior laminoplasty for multilevel cervical myelopathy: a systematic review and meta-analysis. Eur Spine J. doi:10.1007/s00586-013-3043-7 7. Machino M, Yukawa Y, Hida T, Ito K, Nakashima H, Kanbara S, Morita D, Kato F (2012) The prevalence of pre- and postoperative symptoms in patients with cervical spondylotic myelopathy treated by cervical laminoplasty. Spine (Phila Pa 1976) 37(22):E1383– E1388 8. Machino M, Yukawa Y, Hida T, Ito K, Nakashima H, Kanbara S, Morita D, Kato F (2012) Can elderly patients recover adequately after laminoplasty?: a comparative study of 520 patients with cervical spondylotic myelopathy. Spine (Phila Pa 1976) 37(8):667–671 9. Fehlings MG, Smith JS, Kopjar B, Arnold PM, Yoon ST, Vaccaro AR, Brodke DS, Janssen ME, Chapman JR, Sasso RC, Woodard EJ, Banco RJ, Massicotte EM, Dekutoski MB, Gokaslan ZL, Bono CM, Shaffrey CI (2012) Perioperative and delayed complications associated with the surgical treatment of cervical spondylotic myelopathy based on 302 patients from the AOSpine North America Cervical Spondylotic Myelopathy Study. J Neurosurg Spine 16(5):425–432 10. Zhu B, Xu Y, Liu X, Liu Z, Dang G (2013) Anterior approach versus posterior approach for the treatment of multilevel cervical spondylotic myelopathy: a systemic review and meta-analysis. Eur Spine J 22(7):1583–1593
HOW I DO IT - SPINE
Modified open-door laminoplasty for the surgical treatment of cervical spondylotic myelopathy in elderly patients Stefan Alexander König & Uwe Spetzger
Received: 14 January 2014 / Accepted: 19 March 2014 / Published online: 16 April 2014 # Springer-Verlag Wien 2014
Abstract Background The authors describe their experience with a modified version of the standard technique of open-door laminoplasty for the surgical treatment of spondylotic myelopathy in elderly patients with temporary removal of the laminae, extensive decompression, and pre-plating of the laminae beyond the surgical field. Methods Description of surgical anatomy, surgical technique, indications, limitations, complications, and specific perioperative considerations, as well as specific information to give to the patient about surgery and potential risks. A summary of ten key points is given. Conclusions Transection of the laminae on both sides (temporary laminectomy) and pre-plating of the laminae outside of the surgical field has several advantages: better decompression of the spinal canal and the neuroforamina on both sides, easier undercutting of adjacent vertebral arches for craniocaudal decompression, and no risk of spinal cord injury by the screwdriver when attaching plates to the laminae.
craniotome close to the lateral mass on one side. On the other side only the outer layer of compact bone is cut. Usually, laminoplasty involves three laminae. When the block of laminae with their ligaments and spinous processes (the “door”) is opened, this procedure leads to a greenstick fracture of the lateral laminae on the side with the incomplete transection of bone. The bone gutter on the other side is fixed with titanium mini-plates after opening the “door”. The authors prefer a modified technique with transection of the lateral laminae on both sides (Fig. 1b) and a temporary removal of all posterior osseoligamentous structures (Fig. 1c) for a more effective and safer decompression as well as a preplating of the laminae beyond the surgical field (see: Description of the technique). Beside the open-door technique, some institutions use the so-called French-door technique with a splitting of the spinous processes and laminae in the midline [1], but Lee at al. [2] could show that the open-door technique leads to better clinical and radiological results.
Keywords Cervical spondylotic myelopathy . Modified laminoplasty . Surgical technique
Description of the technique
Relevant surgical anatomy The classical technique of open-door laminoplasty for the surgical treatment of cervical spondylotic myelopathy (CSM) includes a transection of the lateral laminae with a Electronic supplementary material The online version of this article (doi:10.1007/s00701-014-2078-9) contains supplementary material, which is available to authorized users. S. A. König (*) : U. Spetzger Neurochirurgische Klinik, Klinikum Karlsruhe, Moltkestr. 90, 76133 Karlsruhe, Germany e-mail: [email protected]
A posterior cervical midline approach is used to expose the lateral masses and the laminae of the involved vertebrae. The patient positioning includes prone position with fixing of the head in a Mayfield clamp in moderate flexion position (‘Concorde position´). The skin incision depends on the number and height of levels being involved as well as on the thickness of the muscles, but usually extends from the external occipital protuberance to the spinous process of T1. The cervical fascia is cut as far medial as possible, right on the edges of the spinous processes on both sides. The insertions of the trapezius muscles, the spinalis muscles, the semispinalis capitis muscles, and the multifidus cervicis muscles are sharply dissected from the spinous processes of the involved
1226
Acta Neurochir (2014) 156:1225–1230
Fig. 1 Surgical steps of posterior decompression and laminoplasty: Creation of a circumscript laminotomy with a diamond drill as an entry point for the craniotome (a). Lamintomy of C5, C6, and C7 with a craniotome (b). Removal of the three laminae in one piece (c). Completing decompression of the spinal chord with a Kerrison punch (d). Finished decompression (e). Replantation of the C7 arch and plate fixation on the short side of the open-door laminoplasty (f). Plate fixation of the C6 arch on the open side of the laminoplasty (g). Finished open-door laminoplasty C5 to C7 (h)
vertebrae. If the spinal stenosis is located in the upper cervical spine, it is also necessary to sharply dissect the rectus capitis posterior muscles and the obliquus capitis inferior muscles from the spinous process of C2. After placing a self-retaining retractor, the lateral masses have to be exposed to have enough space for placing the titanium mini-plates. At the cranial edge of the most cranial vertebral arch, the interlaminar space is enlarged with a 4-millimeter diamond drill (Fig. 1a). The right position for these small entry burr holes is the transition of the lamina to the lateral mass. There is no specific landmark for surgical orientation, but the use of a small diamond drill is helpful to do corrections if the surgeon is far too lateral (cancellous bone of the lateral mass will appear). Afterwards, remnants of the ligamentum flavum are removed with a Kerrison punch to gain enough space for the footplate of the craniotome. The craniotome is used to cut the
lateral laminae near the lateral masses to make sure that the transection is as far lateral as possible (Fig. 1b). The same procedure is repeated on the contralateral side. Afterwards, the laminae (usually three) can be removed en bloc, including the ligaments and spinous processes (Fig. 1c). Now there is enough space for hemostasis of bleeding from epidural veins. Afterwards, the decompression of the spinal cord can be extended cranially and caudally by undercutting the laminae of the adjacent vertebrae (Fig. 1d). In cases of additional foraminal stenosis, it is possible to decompress the cervical nerve roots as well (Fig. 1e). The next step is a complete removal of the ligamenta flava at the inner side of the temporarily removed vertebral arches. That leads to an additional improvement of the sagittal diameter of the spinal canal. When using the classical open-door technique, this step of the operation is much more difficult because there is very little space
Acta Neurochir (2014) 156:1225–1230
1227
for the Kerrison punch, and the risk of spinal cord injury is much higher. Before the laminae are placed back in the surgical field, they are pre-plated with two straight 20-millimeter titanium mini-plates on the side of the gutter and shorter 15-millimeter X-plates on the other side. The screws are self-drilling 4millimeter standard screws. After placing the laminae back into the surgical field, the authors start with fixing the shorter plates to the lateral mass (Fig. 1f), and then the longer plates at the side of the gutter are attached (Fig. 1g), because the adjustment of the width of the gutter is much easier that way. After fixing all laminae on both sides, the open-door laminoplasty is completed (Fig. 1h). The closure includes the placement of a wound drain and sutures of the muscle insertions in the midline to achieve physiological conditions. The whole procedure is shown in the accompanying video.
Indications Symptomatic CSM usually requires surgical therapy. The degenerative process mainly leads to anterior spinal cord compression; thus, an anterior approach is indicated in most cases. If the space-occupying lesion comes from the posterior aspect of the spinal canal, then, of course, the posterior approach should be preferred. Beyond that, elderly patients ≥ 75 years of age are in an exceptional position because the risk for surgical complications related to the anterior approach is higher [3, 4]. Furthermore, these patients show spontaneous bony fusion of cervical vertebral bodies; thus, it would be necessary to drill through the whole intervertebral space or to do a corpectomy when using an anterior approach. In those cases, a posterior approach might be a better choice, even if there is anterior compression of the spinal cord by ligaments and osteophytes (Fig. 2). The posterior approach requires a lordotic or at least a straight configuration of the cervical spine to get enough space for the spinal cord when doing a laminoplasty or laminectomy and fusion [3]. The latter procedure has a higher risk of implant failure in elderly patients due to the high incidence of osteoporosis in that age group. Thus, open-door laminoplasty is a frequent procedure for posterior decompression in elderly patients. Another advantage of laminoplasty compared to laminectomy and fusion is the fact that the range of motion of the cervical spine is less decreased after the procedure. In the authors´ institution, posterior decompression is done by laminectomy and fusion or laminoplasty. Nevertheless, some authors also consider laminectomy without fusion, since there is no statistical proof that laminoplasty is superior to laminectomy without fusion [5]. Thus, cervical laminectomy can be an option for very old patients, with a small number of levels being involved in the cervical spinal stenosis.
Fig. 2 An 81-year-old male patient with CSM. Spinal cord compression resulted from anterior and posterior spondylosis, sagittal MR image (a). An incomplete spontaneous fusion of the C5, C6, and C7 vertebral bodies was detected in the sagittal reconstruction of a preoperative CT scan (b); therefore, posterior decompression was indicated. Narrowing of the spinal canal in the axial plane (c). Temporary removal of the C5, C6, and C7 arch allowed lateral decompression of the spinal cord that can be seen in the coronal reconstruction of a postoperative CT scan (d). Improvement of the spinal canal diameter in the sagittal plane (e; compare with b) and in the axial plane (f; compare with c)
Limitations The success of a posterior decompression is limited in patients with a kyphotic configuration of the cervical spine, because the spinal cord is unable to occupy the additional space from a laminoplasty or laminectomy [3]. In cases of good lordosis, it is possible to decompress the spinal cord even when there is a moderate anterior space-occupying lesion (Fig. 2). If disc herniation, hypertrophic ligaments or osteophytes occupy more than half of the sagittal diameter of the spinal canal, it is better to perform an anterior approach [6]. If the patient suffers from significant neck pain, a laminectomy and fusion are helpful due to the fixation of the facet joints.
1228
If there is secondary worsening of CSM after surgery, an imaging will be necessary. In most cases, the spinal cord cannot be visualized in magnetic resonance imaging (MRI) because of artifacts from the titanium plates. Thus, it might be necessary to do a myleogram and myelo computed tomography (CT).
How to avoid complications The modified technique with a temporary removal and preplating of the laminae outside of the surgical field helps to avoid complications. The risk of spinal cord injury during removal of ligamentum flavum at the inner side of the laminae is completely eliminated because the whole procedure is done outside of the surgical field. Furthermore, there is no risk of Fig. 3 Surgical treatment of a spinal stenosis from C2/3 to C3/4 (a, b). Open-door laminoplasty with the NewBridgeTM system (Blackstone Medical Inc., Springfield, MA, USA). Lateral (c) and anteroposterior (d) radiographs. Coronal (e) and axial (f) CT scan showing an insufficient widening of the spinal canal. Result after revision surgery with the use of the 1.5 Neuro Plating SystemTM (Biomet, Berlin, Germany): sagittal (g) and axial (h) CT scan showing a sufficient decompression of the spinal canal
Acta Neurochir (2014) 156:1225–1230
spinal cord injury by the screwdriver when attaching plates to the laminae.
Specific peri-operative considerations The standard postoperative workup is a CT scan of the cervical spine to document the widening of the spinal canal, as well as the correct position of all mini-plates and screws (Fig. 2d-f). The patient is usually discharged 7 to 10 days after surgery, mainly depending on severity of myelopathy and general condition (most patients are 75 years of age or older). The usual procedure after the hospital discharge is an inpatient rehabilitation treatment in a specific rehab clinic for three weeks. Physiotherapy mainly focuses on the neurological deficits of CSM: gait training, balance training, and
Acta Neurochir (2014) 156:1225–1230
occupational therapy to improve fine motor function of the hands. If CSM is stable or improved after surgery, the authors do not schedule specific follow-up examinations. If there is a secondary worsening of neurological deficits, the patient will be referred to our outpatient clinic by the patient´s neurologist or orthopedic specialist.
Specific information to give to the patient about surgery and potential risks The pre-operative prevalence of motor function impairment in the upper and lower extremities and that of sensory function impairment in the upper extremity is higher than that of other function impairments, whereas impairments in lower Fig. 4 Spinal stenosis from C4 to C7 with spondylotic myelopathy, sagittal MR scan (a). Postoperative result with widening of the spinal canal, sagittal MR scan (b). Anteroposterior radiograph (c) and axial CT scans (df) showing the titanium plates of the 1.5 Neuro Plating SystemTM (Biomet, Berlin, Germany). Beside the laminoplasty of C5 (d), C6 (e), and C7 (f) an undercutting of the C4 arch was performed. Broken mini-plate at C7 after a minor trauma one year after surgery, anteroposterior (g) and lateral (h) radiograph; axial CT scan. There were no clinical symptoms after the trauma, thus, therapy remained conservative
1229
extremity motor function and upper extremity sensory function often persist after surgery [7]. Nevertheless, a prospective study by Machino et al. verified adequate recovery from the symptoms of CSM in a population of elderly patients (age ≥ 75 years) after cervical laminoplasty [8]. The main features of patient information about potential risks of surgery are spinal cord injury, insufficient decompression (Fig. 3) and failure of the osteosynthesis (Fig. 4). Fehlings et al. analysed a population of 302 patients who underwent either an anterior-only, posterior-only or combined anteriorposterior procedures for the treatment of spondylotic myelopathy, and figured out an overall peri-operative complication rate of 15.6 % [9]. The most common complications were cardiopulmonary events (3.0 %), dysphagia (3.0 %), and superficial wound infection (2.3 %). Perioperative worsening of
1230
myelopathy was reported in 1.3 %. After a follow-up of two years there was a delayed complication rate of 4.4 %. Multivariate factors associated with an increased risk of complications included greater age, increased operative time, and the use of combined anterior procedures. Zhu et al. figured out a significantly higher re-operation rate for anterior surgery (8.57 %) compared to posterior surgery (0.3 %) in a meta-analysis that included eight studies [10]. The results of those studies are of importance for the preoperative information of the patient.
Summary 1) Temporary removal of the laminae (= temporary laminectomy) allows complete removal of flavum ligaments at the inner side of the vertebral arch for a more efficient decompression of the spinal cord. 2) Temporary removal of the laminae enables safe attachment of plates and screws—no risk of spinal cord injury. 3) Temporary removal of the laminae allows a better decompression of the lateral spinal canal and the nerve roots on both sides in cases of symptomatic radicular compression. 4) Temporary removal of the laminae allows a better undercutting of the adjacent superior and inferior vertebral arches in cases of stenosis at the level of the disc being adjacent to laminoplasty. 5) Temporary removal of the laminae enables a better hemostasis in the spinal canal on both sides compared to the standard technique. 6) Elderly patients have a significant higher risk of approach-related complications due to an anterior approach; thus, a posterior procedure is a better option. 7) Lordosis is a pre-condition for cervical laminoplasty. 8) Laminoplasty avoids hardware failure from posterior instrumentation, especially in cases of severe osteoporosis. 9) If there is a dominant side of the clinical myelopathy, then the open-side of the laminoplasty should be on the same side. 10) Use as many mini-plates as possible for the fixation of the laminae.
Acta Neurochir (2014) 156:1225–1230 Conflict of interest The authors certify that there is no actual or potential conflict of interest relating to this article.
References 1. Kim SW, Hai DM, Sundaram S, Kim YC, Park MS, Paik SH, Kwak YH, Kim TH (2013) Is cervical lordosis relevant in laminoplasty? Spine J 13(8):914–921 2. Lee DG, Lee SH, Park SJ, Kim ES, Chung SS, Lee CS, Eoh W (2013) Comparison of surgical outcomes after cervical laminoplasty: open-door technique versus French-door technique. J Spinal Disord Tech 26(6):E198–E203 3. Komotar RJ, Mocco J, Kaiser MG (2006) Surgical management of cervical myelopathy: indications and techniques for laminectomy and fusion. Spine J 6(6 Suppl):252S–267S 4. König SA, Ranguis S, Spetzger U (2013) Management of complex cervical instability. J Neurol Surg A Cent Eur Neurosurg. doi:10. 1055/s-0033-1345095 5. Ratliff JK, Cooper PR (2003) Cervical laminoplasty. A critical review. J Neurosurg 98(3 Suppl):230–238 6. Liu X, Min S, Zhang H, Zhou Z, Wang H, Jin A (2013) Anterior corpectomy versus posterior laminoplasty for multilevel cervical myelopathy: a systematic review and meta-analysis. Eur Spine J. doi:10.1007/s00586-013-3043-7 7. Machino M, Yukawa Y, Hida T, Ito K, Nakashima H, Kanbara S, Morita D, Kato F (2012) The prevalence of pre- and postoperative symptoms in patients with cervical spondylotic myelopathy treated by cervical laminoplasty. Spine (Phila Pa 1976) 37(22):E1383– E1388 8. Machino M, Yukawa Y, Hida T, Ito K, Nakashima H, Kanbara S, Morita D, Kato F (2012) Can elderly patients recover adequately after laminoplasty?: a comparative study of 520 patients with cervical spondylotic myelopathy. Spine (Phila Pa 1976) 37(8):667–671 9. Fehlings MG, Smith JS, Kopjar B, Arnold PM, Yoon ST, Vaccaro AR, Brodke DS, Janssen ME, Chapman JR, Sasso RC, Woodard EJ, Banco RJ, Massicotte EM, Dekutoski MB, Gokaslan ZL, Bono CM, Shaffrey CI (2012) Perioperative and delayed complications associated with the surgical treatment of cervical spondylotic myelopathy based on 302 patients from the AOSpine North America Cervical Spondylotic Myelopathy Study. J Neurosurg Spine 16(5):425–432 10. Zhu B, Xu Y, Liu X, Liu Z, Dang G (2013) Anterior approach versus posterior approach for the treatment of multilevel cervical spondylotic myelopathy: a systemic review and meta-analysis. Eur Spine J 22(7):1583–1593
