Osteoplastic laminoplasty for cervical myeloradiculopathy secondary to ossification of the posterior longitudinal ligament

Is anterior decompression and fusion superior to laminoplasty for cervical myelopathy due to ossification of posterior longitudinal ligament? A systematic review and meta-analysis

Context: Considerable controversy exists over surgical procedures for ossification of the posterior longitudinal ligament (OPLL).Objective: The purpose of the meta-analysis was to compare the clinical outcome of anterior decompression and fusion (ADF) with laminoplasty (LAMP) in treatment of cervical myelopathy due to OPLL.Methods: PubMed, EMBASE and the Cochrane Register of Controlled Trials database were searched to identify potential clinical studies compared ADF with LAMP for cervical myelopathy owing to OPLL. We also manually searched the reference lists of articles and reviews for possible relevant studies. Thirteen studies with 1120 patients were included in our analysis. Subgroup analyses were performed by the canal occupying ratio of OPLL.Results: Overall, the mean preoperative Japanese Orthopaedic Association (JOA) score was similar between two groups. Compared with LAMP group, ADF group was higher at the mean postoperative JOA scores and mean recovery rate, reoperation rate, and longer at mean operation time. There was not significantly different in mean blood loss and complication rate between two groups. In subgroup analysis, ADF had a higher mean postoperative JOA score and recovery rate than LAMP in cases of OPLL with occupying ratios ≥ 50%, while those difference were not found in cases of OPLL with occupying ratios < 50%.Conclusion: ADF achieves better neurological improvement compared with LAMP in treatment of cervical myelopathy due to OPLL, especially in cases of OPLL with occupying ratios ≥ 50%. Complication rate is similar between two groups, but ADF can increase the risk of reoperation.

Clinical outcomes of late decompression surgery following cervical spinal cord injury with pre-existing cord compression

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

The purpose of the current study was to examine the effectiveness of late decompression surgery for traumatic cervical spinal cord injury (CSCI) with pre-existing cord compression.

SETTING

Murayama Medical Center, National Hospital Organization, Tokyo, Japan.

METHODS

In total 78 patients with traumatic CSCI without bone injury hospitalized in 2012-2015 in our institute for rehabilitation after initial emergency care were divided into four groups according to the compression rate (CR) of the injured level and whether or not decompression surgery was performed. Neurological status was evaluated by American Spinal Injury Association impairment scale (AIS), Barthel index, and Spinal Cord Independence Measure (SCIM).

RESULTS

In the severe compression group (CR ≥ 40%), >2 grade improvement in the AIS was observed in 30% of patients with surgical treatment, although it was not observed in any patient without surgery. The SCIM improvement rate at discharge was 60% in the surgical treatment group and 20% in the non-surgical treatment group. In the minor compression group (CR < 40%), >2 grade improvement in the AIS was observed in 18% of patients with surgical treatment and in 11% without surgery. The SCIM improvement rate at discharge was 52% in the surgical treatment group and 43% in the non-surgical treatment group.

CONCLUSIONS

These results indicate that surgical treatment has an advantage for patients following traumatic CSCI with severe cord compression. In contrast, surgical efficacy is not proved for CSCI patients without severe cord compression.

In vivo 3D kinematic changes in the cervical spine after laminoplasty for cervical spondylotic myelopathy

Object

Cervical laminoplasty is an effective procedure for decompressing the spinal cord at multiple levels, but restriction of neck motion is one of the well-known complications of the procedure. Although many authors have reported on cervical range of motion (ROM) after laminoplasty, they have focused mainly on 2D flexion and extension on lateral radiographs, not on 3D motion (including coupled motion) nor on precise intervertebral motion. The purpose of this study was to clarify the 3D kinematic changes in the cervical spine after laminoplasty performed to treat cervical spondylotic myelopathy.

Methods

Eleven consecutive patients (6 men and 5 women, mean age 68.1 years, age range 57–79 years) with cervical spondylotic myelopathy who had undergone laminoplasty were included in the study. All patients underwent 3D CT of the cervical spine in 5 positions (neutral, 45° head rotation left and right, maximum head flexion, and maximum head extension) using supporting devices. The scans were performed preoperatively and at 6 months after laminoplasty. Segmental ROM from Oc–C1 to C7–T1 was calculated both in flexion-extension and in rotation, using a voxel-based registration method.

Results

Mean C2–7 flexion-extension ROM, equivalent to cervical ROM in all previous studies, was 45.5° ± 7.1° preoperatively and 35.5° ± 8.2° postoperatively, which was a statistically significant 33% decrease. However, mean Oc–T1 flexion-extension ROM, which represented total cervical ROM, was 71.5° ± 8.3° preoperatively and 66.5° ± 8.3° postoperatively, an insignificant 7.0% decrease. In focusing on each motion segment, the authors observed a statistically significant 22.6% decrease in mean segmental ROM at the operated levels during flexion-extension and a statistically insignificant 10.2% decrease during rotation. The most significant decrease was observed at C2–3. Segmental ROM at C2–3 decreased 24.2% during flexion-extension and 21.8% during rotation. However, a statistically insignificant 37.2% increase was observed at the upper cervical spine (Oc–C2) during flexion-extension. The coupling pattern during rotation did not change significantly after laminoplasty.

Conclusions

In this first accurate documentation of 3D segmental kinematic changes after laminoplasty, Oc–T1 ROM, which represented total cervical ROM, did not change significantly during either flexion-extension or rotation by 6 months after laminoplasty despite a significant decrease in C2–7 flexion-extension ROM. This is thought to be partially because of a compensatory increase in segmental ROM at the upper cervical spine (Oc–C2).

Inflammatory cascades mediate synapse elimination in spinal cord compression

Background

Cervical compressive myelopathy (CCM) is caused by chronic spinal cord compression due to spondylosis, a degenerative disc disease, and ossification of the ligaments. Tip-toe walking Yoshimura (twy) mice are reported to be an ideal animal model for CCM-related neuronal dysfunction, because they develop spontaneous spinal cord compression without any artificial manipulation. Previous histological studies showed that neurons are lost due to apoptosis in CCM, but the mechanism underlying this neurodegeneration was not fully elucidated. The purpose of this study was to investigate the pathophysiology of CCM by evaluating the global gene expression of the compressed spinal cord and comparing the transcriptome analysis with the physical and histological findings in twy mice.

Methods

Twenty-week-old twy mice were divided into two groups according to the magnetic resonance imaging (MRI) findings: a severe compression (S) group and a mild compression (M) group. The transcriptome was analyzed by microarray and RT-PCR. The cellular pathophysiology was examined by immunohistological analysis and immuno-electron microscopy. Motor function was assessed by Rotarod treadmill latency and stride-length tests.

Results

Severe cervical calcification caused spinal canal stenosis and low functional capacity in twy mice. The microarray analysis revealed 215 genes that showed significantly different expression levels between the S and the M groups. Pathway analysis revealed that genes expressed at higher levels in the S group were enriched for terms related to the regulation of inflammation in the compressed spinal cord. M1 macrophage-dominant inflammation was present in the S group, and cysteine-rich protein 61 (Cyr61), an inducer of M1 macrophages, was markedly upregulated in these spinal cords. Furthermore, C1q, which initiates the classical complement cascade, was more upregulated in the S group than in the M group. The confocal and electron microscopy observations indicated that classically activated microglia/macrophages had migrated to the compressed spinal cord and eliminated synaptic terminals.

Conclusions

We revealed the detailed pathophysiology of the inflammatory response in an animal model of chronic spinal cord compression. Our findings suggest that complement-mediated synapse elimination is a central mechanism underlying the neurodegeneration in CCM.

A less-invasive cervical laminoplasty for spondylotic myelopathy that preserves the semispinalis cervicis muscles and nuchal ligament

Object

Modified cervical laminoplasty techniques have been developed to reduce postoperative axial neck pain and preserve function in patients with cervical spondylotic myelopathy (CSM). However, the previous studies demonstrating satisfactory surgical outcomes had a retrospective design. Here, the authors aimed to prospectively evaluate the 2-year outcomes of a modified cervical laminoplasty technique for CSM that preserves the paravertebral muscles.

Methods

Outcomes were analyzed for 40 patients (22 men and 18 women; mean age, 66.6 years; age range 44–92 years) with CSM who underwent C4–6 laminoplasty with C-3 and C-7 partial laminectomies or C-3 total and C-7 partial laminectomies and received hydroxyapatite spacers. Neurological, pain severity, and spinal radiographic evaluations were performed preoperatively and at 3, 6, 12, 18, and 24 months postoperatively. Plain radiography and MRI of the cervical spine were performed to evaluate the range of motion (ROM), sagittal alignment, and cross-sectional areas of the deep extensor muscles. The extent of bone–spacer bonding and bony union at the gutter was assessed by CT.

Results

The mean preoperative Japanese Orthopaedic Association CSM score was 10.2, but it increased to 14.4 by 24 months after surgery. Eleven patients had axial neck pain preoperatively, but only 3 reported mild pain at 24 months, and in all 3 cases the pain was mild. The mean angle of lordosis was 11.7° preoperatively and 12.0° 2 years postoperatively. Although the ROM at the C2–7 levels was significantly reduced 3 months postoperatively, an increasing trend was observed up to 12 months, and 86% of the preoperative ROM was achieved by 2 years postoperatively. The mean paravertebral muscle cross-sectional areas were 833 ± 215 mm2 preoperatively and 763 ± 197 mm2 24 months postoperatively, but the difference was not statistically significant. The rates of bone–spacer bonding and bony union at the gutter were low during the early stages but increased to 90% and 93%, respectively, by 2 years after surgery.

Conclusions

The modified laminoplasty technique used in this study ensured very good neurological status and ROM after 2 years and was associated with low incidences of axial neck pain and serious complications. This simple and easy operative method could benefit future laminoplasty protocols.

Laminoplasty techniques for the treatment of multilevel cervical stenosis

Laminoplasty is one surgical option for cervical spondylotic myelopathy. It was developed to avoid the significant risk of complications associated with alternative surgical options such as anterior decompression and fusion and laminectomy with or without posterior fusion. Various laminoplasty techniques have been described. All of these variations are designed to reposition the laminae and expand the spinal canal while retaining the dorsal elements to protect the dura from scar formation and to preserve postoperative cervical stability and alignment. With the right surgical indications, reliable results can be expected with laminoplasty in treating patients with multilevel cervical myelopathy.

Cervical spondylotic myelopathy associated with kyphosis or sagittal sigmoid alignment: outcome after anterior or posterior decompression

Object

The effects of sagittal kyphotic deformities or mechanical stress on the development of cervical spondylotic myelopathy, or the reduction and fusion of kyphotic sagittal alignment have not been consistently documented. The aim in this study was to determine the effects of kyphotic sagittal alignment of the cervical spine in terms of neurological morbidity and outcome after 2 types of surgical intervention.

Methods

The authors retrospectively reviewed the records of 476 patients who underwent cervical spine surgeries for spondylotic myelopathy between 1993 and 2006 at their university medical center. Among these were identified 43 patients—30 men and 13 women, with a mean age of 58.8 years—who had cervical kyphosis exceeding 10° on preoperative sagittal lateral radiographs obtained in the neutral position, and their cases were analyzed in this study. Anterior decompression with interbody fusion was conducted in 28 patients, and en bloc open-door C3–7 laminoplasty in 15 patients. Both pre- and postoperative neurological, radiographic, and MR imaging findings were assessed in both surgical groups.

Results

The mean preoperative kyphotic angle in all 43 patients was 15.9 ± 5.9° in the neutral position. Segmental instability was noted in 26 patients (61%) and reversed dynamic spinal canal stenosis at the level above the local kyphosis in 22 (51%). Preoperative T2-weighted MR images showed high-intensity signal within the cord at and around the level of maximal compression or segmental instability in 28 patients (65%). The mean kyphotic angle in both the neutral and flexion positions was significantly smaller at 4–6 weeks after surgery in the anterior spondylectomy group than in the laminoplasty group (p < 0.001). Furthermore, the angle in the neutral position was significantly smaller on follow-up in the anterior spondylectomy group than in the laminoplasty group (p = 0.034). The transverse area of the spinal cord was significantly larger in the anterior spondylectomy group than in the laminoplasty group on follow-up (p = 0.037). Preoperative neurological scores (assessed using the Japanese Orthopaedic Association scale) and improvement on follow-up ≥ 2 years after treatment (average 3.3 years) were not significantly different between the 2 groups; however, there was a significant difference in Japanese Orthopaedic Association score at 4–6 weeks postoperatively (p = 0.047).

Conclusions

Kyphotic deformity and mechanical stress in the cervical spine may play an important role in neurological dysfunction. In a select group of patients with kyphotic deformity ≥ 10°, adequate correction of local sagittal alignment may help to maximize the chance of neurological improvement.

Long-term outcome of laminectomy and instrumented fusion for cervical ossification of the posterior longitudinal ligament

Between January 2000 and December 2003, a total of 83 patients (64 men and 19 women, average age: 56.4 years, range: 42-78 years) who underwent posterior laminectomy and instrumented fusion for ossification of the posterior longitudinal ligament (OPLL) were included in this study to investigate the long-term outcome of this surgical option and clarify which factors affect the prognosis. After an average 4.8-year follow-up, the mean Japanese Orthopaedic Association (JOA) score significantly increased from 9.2 +/- 1.3 points before operation to 14.2 +/- 0.9 points at the latest follow-up (P < 0.01). The improvement rate (IR) of neurological function ranged from 11.1 to 87.5%, with a mean of 62.4 +/- 13.2%. Among 83 patients, 59 (71.1%) patients had a good prognosis (IR > or = 50%), and the other 24 (28.9%) patients had a poor prognosis (IR < 50%). Postoperative nerve root palsy was the main complication in this series. Radiographic study showed that whilst improving cervical lordosis could provide a better decompression effect and good prognosis, it could have simultaneously contributed to the high incidence of postoperative nerve root palsy.

Delayed dural laceration by hydroxyapatite spacer causing tetraparesis following double-door laminoplasty

OBJECT

The authors describe 4 cases of delayed dural laceration by hydroxyapatite (HA) spacer causing tetra-paresis following double-door laminoplasty. There are few reports of iatrogenic spinal cord lesions developing after double-door laminoplasty, although some complications such as postoperative C-5 paralysis or axial symptoms have been reported. The purpose of this report is to draw attention to the possibility of delayed dural laceration and its triggering mechanism.

METHODS

One hundred thirty patients treated for cervical myelopathy were followed up for an average of 2 years and 9 months after laminoplasty.

RESULTS

Four patients experienced aggravation of cervical myelopathy. Anterior dislodgement of HA spacers was shown on plain lateral radiographs. Follow-up T2-weighted magnetic resonance imaging demonstrated that the dislodged HA spacers were surrounded by cerebrospinal fluid at the time of aggravation. The dislodged HA spacers were removed and the dural membrane defects were repaired by patching with the fascia of the gluteus maximus muscle. The preoperative symptoms improved after the second operation in all patients.

CONCLUSIONS

It is hypothesized that the loosening of the HA spacer in split spinous processes could occur with the movement of the cervical spine and/or the breakage of the suture before bone bonding. Anterior dislodgement of the HA spacer toward the spinal canal would cause dural laceration by direct friction between the dural membrane and the dislodged HA spacer, resulting in clinical aggravation. Despite the well-documented advantages of using HA spacers for double-door laminoplasty, possible laceration due to a dislodged HA spacer should be considered as a late complication.

Suspended laminoplasty for wide posterior cervical decompression and intradural access: results, advantages, and complications

Object. Cervical laminoplasty is a recognized technique commonly used for multilevel posterior cervical decompression, and it is favored over laminectomy for maintaining spinal stability. Traditional hinge techniques, however, limit lateral exposure on one side and can limit dural exposure. The authors present their experience with a modified laminoplasty technique incorporating complete laminectomy and placement of titanium miniplate instrumentation. This method allows wide bilateral posterior decompression and unobscured dural access.

Methods. Twenty-eight patients (mean age 57 years) underwent cervical laminoplasty during a 4-year period. Twenty-seven patients presented with progressive cervical myelopathy. Seventeen patients (61%) had degenerative spondylotic stenosis; nine (32%) underwent resection of an intradural neoplasm. A mean of 3.5 levels were exposed and reconstructed. The follow-up period ranged from 4 months to 4 years (mean 15 months). The mean angular extension—flexion displacement measured between C-1 and C-7 was unchanged postoperatively, with preserved mobility across laminoplasty-treated segments in all patients. The anteroposterior diameter of the spinal canal increased 3.6 mm (27.2%) postoperatively (p = 0.004). In one patient an asymptomatic postoperative kyphosis developed. There were five cases of postoperative infection. One superficial infection resolved after intravenous antibiotic therapy alone, and four deep infections required surgical reexploration.

Conclusions. The advantages of this technique over other laminoplasty methods include wide lateral spinal canal and intradural access, as well as preserved motion with partial restoration of the posterior tension band.

Cervical laminoplasty: a critical review

OBJECT

The technique of cervical laminoplasty was developed to decompress the spinal canal in patients with multi-level anterior compression caused by ossification of the posterior longitudinal ligament or cervical spondylosis. There is a paucity of data confirming its superiority to laminectomy with regard to neurological outcome, preserving spinal stability, preventing postlaminectomy kyphosis, and the development of the "postlaminectomy membrane."

METHODS

The authors conducted a metaanalysis of the English-language laminoplasty literature, assessing neurological outcome, change in range of motion (ROM), development of spinal deformity, and complications. Seventy-one series were reviewed, comprising more than 2000 patients. All studies were retrospective, uncontrolled, nonrandomized case series. Forty-one series provided postoperative recovery rate data in which the Japanese Orthopaedic Association Scale was used for assessing myelopathy. The mean recovery rate was 55% (range 20-80%). The authors of 23 papers provided data on the percentage of patients improving (mean approximately 80%). There was no difference in neurological outcome based on the different laminoplasty techniques or when laminoplasty was compared with laminectomy. There was postlaminoplasty worsening of cervical alignment in approximately 35% and with development of postoperative kyphosis in approximately 10% of patients who underwent long-term follow-up review. Cervical ROM decreased substantially after laminoplasty (mean decrease 50%, range 17-80%). The authors of studies with long-term follow up found that there was progressive loss of cervical ROM, and final ROM similar to that seen in patients who had undergone laminectomy and fusion. In their review of the laminectomy literature the authors could not confirm the occurrence of postlaminectomy membrane causing clinically significant deterioration of neurological function. Postoperative complications differed substantially among series. In only seven articles did the writers quantify the rates of postoperative axial neck pain, noting an incidence between 6 and 60%. In approximately 8% of patients, C-5 nerve root dysfunction developed based on the 12 articles in which this complication was reported.

CONCLUSIONS

The literature has yet to support the purported benefits of laminoplasty. Neurological outcome and change in spinal alignment are similar after laminectomy and laminoplasty. Patients treated with laminoplasty develop progressive limitation of cervical ROM similar to that seen after laminectomy and fusion.

A new technique for exposure of the cervical spine laminae. Technical note

The author describes a new technique for exposure of the cervical spine laminae in which the attachments of the semispinalis cervicis and multifidus muscles to the spinous processes are left untouched. It provides a conservative exposure through which a diverse range of posterior cervical surgeries can be performed. In contrast to conventional cervical approaches, none of the muscular attachments to the spinous processes is compromised. In this paper the author describes the technical details and discusses the applications of the procedure.

Long-term follow-up review of suspension laminotomy for cervical compression myelopathy

This study compared the long-term outcome of cervical spondylotic myelopathy (CSM) with that of the ossification of the posterior longitudinal ligament of the cervical spine (OPLL) after suspension laminotomy, which was developed in the authors' clinic. Seventy-six patients who received follow-up care for more than 5 years were available for analysis. The duration of the follow-up period averaged 97.8 months (range 61-160 months). Radiological and neurological analyses were performed in these 76 patients (50 with CSM and 26 with OPLL). There were no differences in sex, age, follow-up period, and preoperative neurological status between the two groups. In the quantitative study of the dural configuration, 43 patients (86%) with CSM and 17 patients (65.4%) with OPLL attained complete decompression 1 month after surgery. At long-term follow-up review, complete decompression was maintained in 42 patients (84%) with CSM but in only seven patients (26.9%) with OPLL. The neurological evaluation improved markedly at early follow up in both groups but declined insignificantly at the last follow-up review, particularly in the OPLL group. Of 12 patients (24%) with CSM and 10 patients (38.5%) with OPLL whose neurological recovery grades later deteriorated, four (8%) with CSM and nine (34.6%) with OPLL demonstrated reconstriction causing spinal cord compression at long-term follow-up review. For the remaining eight patients (16%) with CSM, who were older than 70 years on average at last follow-up review, no radiological explanation was found. These long-term results indicate that OPLL does not resolve as well as CSM after suspension laminotomy; they both may have late deterioration due to reconstriction that occurs occasionally in CSM and frequently in OPLL.

Cervical laminoplasty in patients with ossification of the posterior longitudinal ligaments

Cervical laminoplasty was the operation used for myeloradiculopathy secondary to ossification of the posterior longitudinal ligaments. Some 57 patients were followed up for 5-13 years (average: 7.8 years). The spinal canal from C3 to C7 was surgically opened en bloc unilaterally with spacer bone grafting to maintain the laminae in a 'kept open' position and thus to implement posterior decompression. No serious major surgery-related complications were observed. Favourable results were obtained in 42 patients (74%), but those with advanced preoperative neurological symptoms did not improve. Patients with spinal canals seriously compromised by anterior ossified lesions recovered poorly. We concluded that laminoplasty is recommended for cervical myeloradiculopathy due to ossified posterior longitudinal ligaments for selected patients, but surgery should be done before the patient has developed serious neurological damage.