Long-term results of double-door laminoplasty using hydroxyapatite spacers in patients with compressive cervical myelopathy

Effects of Preoperative Cervical Range of Motion on Clinical Outcomes Following Posterior Decompression: A Multicenter Study of Patients With Cervical Ossification of the Posterior Longitudinal Ligament

Study DesignRetrospective multicenter study.ObjectivesTo investigate the impact of preoperative cervical range of motion (ROM) on clinical outcomes after posterior decompression for cervical ossification of the posterior longitudinal ligament (OPLL).MethodsWe analyzed data from 156 patients with cervical OPLL who underwent posterior decompression and were followed for at least 2 years. Patients were divided into two groups based on preoperative gap ROM, which was a novel indicator representing the difference between flexion and extension ROM: the gROM <0° and >0° groups, and their outcomes were compared.ResultsThere were no significant differences in patient demographics or surgical details between the gROM <0° and >0° groups. The gROM <0° group exhibited less lordosis in C2-7 angles before and after surgery compared to the gROM >0° group. Cervical ROM significantly decreased following posterior decompression regardless of whether preoperative gROM was <0° or >0°. Meanwhile, the incidence of perioperative complications was similar between the two groups. Furthermore, both groups showed significant improvement in Japanese Orthopaedic Association (JOA) scores postoperatively; however, there were no significant group differences in JOA scores, recovery rates, or visual analog scale for neck pain between the two groups at the preoperation and final follow-up.ConclusionsThe incidence of perioperative complications and postoperative clinical outcomes were comparable regardless of the magnitude of preoperative cervical gROM. Although cervical ROM decrease postoperatively, posterior decompression for cervical OPLL can offer favorable clinical outcomes irrespective of the preoperative cervical ROM magnitude, consequently.

Laminoplasty in Motion: Evolving Techniques and Complications

Cervical laminoplasty is an increasingly popular surgical option for the treatment of cervical spondylotic myelopathy (CSM) and ossification of the posterior longitudinal ligament (OPLL). Over the past few decades, there have been substantial developments in both surgical technique and hardware options. As the field of cervical surgery rapidly evolves, there is a timely need to reassess the evolving complications associated with newer techniques. This review aims to synthesize the available literature on cervical laminoplasty and associated mechanical complications pertaining to different laminoplasty hinge fixation options.

Plate-only open-door laminoplasty is associated with durable, significantly improved clinical outcomes and a very low reoperation rate for progressive spondylosis or adjacent segment disease: average 8-year follow-up

BACKGROUND CONTEXT

Multilevel cervical myelopathy is a common cause of spinal cord dysfunction in adults. Surgical intervention via laminoplasty can provide satisfactory clinical outcomes by expansive decompression of the spinal cord. Traditional suture or bone graft techniques have been associated with insufficient fixation, leading to premature closure and subsequent neurological deterioration. In contrast, plated laminoplasty has been shown to provide stable fixation to maintain canal enlargement, but longer-term outcomes are lacking.

PURPOSE

To evaluate longer-term clinical outcomes and reoperations associated with plate-only open-door laminoplasty.

STUDY DESIGN

Retrospective review of prospectively collected data.

PATIENT SAMPLE

Postoperative patients who underwent plate-only open door laminoplasty with minimum 5-year follow up.

OUTCOME MEASURES

modified Japanese Orthopaedic Association (mJOA) score, Neck Disability Index (NDI), and 12-item Short Form Health Survey (SF-12).

METHODS

All patients at a single academic institution who underwent plate-only open-door cervical laminoplasty from 9/1/2006 to 9/1/2016 were identified to ensure minimum 5 year follow up. Clinical outcomes included the modified Japanese Orthopaedic Association (mJOA) score, the Neck Disability Index (NDI), and the 12-item Short Form Health Survey (SF-12). The occurrence of any repeat operations on the cervical spine was evaluated, as well as its cause. The study team attempted to contact all eligible patients to achieve at least 5 years postoperative follow-up. Pairwise t tests were performed to compare clinical outcomes at preoperative, 6 months, 1-year, and final postoperative follow-up with an α level of 0.05.

RESULTS

A total of 774 met the initial inclusion criteria, of which 157 were included in the study (20.3%). Most common reasons for exclusion included inability to reach after 3 attempts (49.48%), inactive phone numbers (20.28%), and patient declining (3.49%). Included patients had an average age of 60.66±10.63 and an average follow-up time of 8.37±2.57 years (minimum 5 years). mJOA scores (preoperative 11.59±2.16) improved significantly at 6-months (14.57±2.07, p<.001), 1-year (15.19±1.95, p<.001), and final follow-up (14.59±2.63, p<.001). NDI (preoperative 33.89±18.54) improved significantly at 6 months (27.89±19.72, p=.03), 1-year (25.96±19.79, p=.01) and final follow-up (17.88±17.17, p<.001). SF-12 MCS (preoperative 44.73) improved significantly at 6 months (52.01, p=.001), 1-year (51.62, p=.008), and final follow-up (52.32, p<.001). No patient underwent reoperations for plate failure or canal closure with recurrent stenosis. Reoperations for progressive spondylosis during the follow up period were rare and occurred in only three patients for new onset radiculopathy (1.9%) and two patients for myelopathy (1.3%) at an average of 3.2 years postoperative. There were no reoperations performed for adjacent segment disease.

CONCLUSIONS

At a minimum of 5 years and an average of more than 8 years postoperative, laminoplasty was associated with significant and sustained improvements in mJOA, NDI, and SF-12 MCS. Importantly, no patients underwent revision surgery for plate failure or recurrent canal closure. Reoperations for new onset radiculopathy and myelopathy were also very rare over the 8-year average follow-up period, with no reoperations for adjacent segment disease. Plate-only laminoplasty is a durable means of treating multilevel myelopathy with excellent longer-term outcomes and a very low risk of reoperation, either for premature closure or the inevitable spondylotic changes that occur over time in patients with similar baseline characteristics to the study population.

Impact of C3 laminectomy on cervical sagittal alignment in cervical laminoplasty: a prospective, randomized controlled trial comparing clinical and radiological outcomes between C3 laminectomy with C4-C6 laminoplasty and C3-C6 laminoplasty

BACKGROUND CONTEXT

C3 laminectomy in cervical laminoplasty is a modified laminoplasty technique that can preserve the semispinalis cervicis muscle attached to the C2 spinous process. Several previous studies have shown that this technique can lead to better outcomes of postoperative axial neck pain and C2-C3 range of motion (ROM) than conventional cervical laminoplasty. However, there is still a lack of understanding of total and proportional postoperative cervical sagittal alignment outcomes.

PURPOSE

To assess the effects of C3 laminectomy in cervical laminoplasty on postoperative cervical alignment and clinical outcomes.

DESIGN

A single-center, patient-blinded, randomized controlled trial.

PATIENT SAMPLE

We included consecutive 126 patients diagnosed with cervical spondylotic myelopathy (CSM) or ossification of posterior longitudinal ligament (OPLL) who were scheduled for cervical laminoplasty from March 2017 to January 2020.

OUTCOME MEASURES

The primary outcome measures were C2-C7 Cobb angle (CA) and neck disability index (NDI). Secondary outcomes measures included other clinical outcomes and radiographic parameters including segmental Cobb angle and presence of C2-C3 interlaminar fusion.

METHODS

Patients were randomly allocated to either the C3 laminectomy with C4-C6 laminoplasty group (LN group) or the C3-C6 laminoplasty group (LP group) at a 1:1 ratio. Laminoplasty was performed using a unilateral open-door technique and stabilized with titanium mini plates. A linear mixed model analysis was employed to examine the longitudinal data from postoperative 1-year through 3-year. Additional analysis between three types of cervical sagittal alignment morphology was done.

RESULTS

Among 122 patients who were randomly allocated to one of two groups (LN group, n=61; LP group, n=61), modified intent-to-treat analysis was done for 109 patients (LN group, n=51, LP group, n=58) who had available at least a year of postoperative data. Postoperative C2-C7 CA was not significantly different between the two groups. However, NDI was significantly different between the two groups (12.8±1.0 in the LN group vs 8.6±1.0 in LP group, p=.005), which exceeded the minimum clinically important difference (MCID). The postoperative C2-C3 CA was significantly greater in the LN group (7.1±0.5° in LN group vs 3.2±0.5° in LP group, p<.001) while C4-C7 CA was significantly smaller in the LN group (3.9±0.8° in LN group vs 7.7±0.7° in LP group, p<.001) with greater cSVA in the LN group (31.6±1.4 mm in LN group vs 25.5±1.3 mm in LP group at postoperative 3-year, p=.002). Postoperative Euro-Quality of Life-5 Dimension (EQ-5D), numerical rating scores for neck pain (NRS-N) were significantly better in the LP group than in the LN group (all p<.05) and only EQ-5D surpassed the MCID. The C2-C3 fusion rate was significantly different between the LN group (9.8%) and the LP group (44.8%) (p<.001). The LN group showed a higher prevalence of a specific cervical alignment morphology characterized by a sigmoid shape with proximal lordosis and distal kyphosis (S curve). This S curve demonstrated significantly unfavorable outcomes across multiple outcome variables.

CONCLUSION

The impact of C3 laminectomy in cervical laminoplasty on postoperative kyphosis among patients with CSM or OPLL did not significantly differ from that of C3-C6 laminoplasty. However, C3 laminectomy in cervical laminoplasty might result in an unfavorable clinical outcome with an unbalanced cervical sagittal alignment characterized by a sigmoid shape with proximal lordosis and distal kyphosis.

Effect of preoperative dynamic cervical sagittal alignment on the loss of cervical lordosis after laminoplasty

PURPOSE

Cervical laminoplasty (CLP) is a developed surgical procedure for the treatment of cervical spondylotic myelopathy (CSM), but only a few of those studies focus on preoperative dynamic cervical sagittal alignment and the study of different degrees of loss of cervical lordosis (LCL) is lacking. This study aimed to analyze patients who underwent CLP to investigate the effect of cervical extension and flexion function on different degrees of LCL.

METHODS

In this retrospective case-control study, we analyzed 79 patients who underwent CLP for CSM between January 2019 and December 2020. We measured the cervical sagittal alignment parameters on lateral radiographs (neutral, flexion, and extension positions) and used Japanese Orthopedic Association (JOA) score to assess clinical outcomes. We defined the extension ratio (EXR) as 100 × Ext ROM (cervical range of extension)/ROM (cervical range of motion). We observed the relationships between collected variables (demographic and radiological variables) and LCL. Patients were classified into the following three groups according to the LCL: stability group: (LCL ≤ 5°); mild loss group (5° < LCL ≤ 10°); and severe loss group (LCL > 10°). We compared the differences of collected variables (demographic, surgical and radiological variables) among the three groups.

RESULTS

Seventy-nine patients were enrolled (mean age 62.92 years; 51 men, 28 women) in the study. Among the three groups, cervical Ext ROM was the best in the stability group (p < 0.01). Compared with the stability group, range of flexion (Flex ROM) was significantly higher (p < 0.05) and EXR was significantly lower (p < 0.01) in the severe loss group. Compared with the severe loss group, JOA recovery rates were better (p < 0.01) in the stability group. Receiver-operating characteristic curve (ROC) analysis to predict LCL > 10° (area under the curve = 0.808, p < 0.001). The cutoff value for EXR was 16.80%, with sensitivity and specificity of 72.5% and 82.4%, respectively.

CONCLUSION

CLP should be carefully considered for patients with a preoperative low Ext ROM and high Flex ROM, as a significant kyphotic change is likely to develop after surgery. EXR is a useful and simple index to predict significant kyphotic changes.

＜Editors' Choice＞ Neck pain after cervical laminoplasty is associated with postoperative atrophy of the trapezius muscle

Cervical laminoplasty is a safe and effective treatment for cervical myelopathy. However, it has a higher frequency of postoperative axial pain than other methods. A variety of causes of postoperative axial pain have been reported, but these have not been fully elucidated. This study aimed to investigate the association between postoperative axial pain and changes in the posterior neck muscles before and after surgery. The study included 93 patients with cervical myelopathy who underwent surgery at our institute between June 2010 and March 2013. The patients with greater preoperative and 1-year postoperative neck pain visual analog scale scores comprised the neck pain group. The cross-sectional area of the cervical posterior extensor muscles and the trapezius muscle were measured by magnetic resonance imaging before and 1 year after surgery at the C3/4, C4/5, and C5/6 levels to compare with neck pain. The total cross-sectional area atrophy rate (C3/C4, C4/C5, and C5/C6) of the trapezius muscle was significantly larger in patients with neck pain (12.8 ± 13.2) than in those without (6.2 ± 14.4; p<0.05). The cross-sectional area atrophy rate of the trapezius muscle at only the C5/6 level was significantly higher in patients with neck pain (16.7 ± 11.7) compared to those without (3.3 ± 14.4; p<0.001). No significant differences were found in the cross-sectional areas of the cervical posterior extensor muscles. Trapezius atrophy, especially at the lower cervical vertebrae, was associated with neck pain after cervical laminoplasty.

Long-term functional outcome of surgical treatment for degenerative cervical myelopathy

OBJECTIVE

Degenerative cervical myelopathy (DCM) is a major global cause of spinal cord dysfunction. Surgical treatment is considered a safe and effective way to improve functional outcome, although information about long-term functional outcome remains scarce despite increasing longevity. The objective of this study was to describe functional outcome 10 years after surgery for DCM.

METHODS

A prospective observational cohort study was undertaken in a university-affiliated neurosurgery department. All patients who underwent surgery for DCM between 2008 and 2010 as part of the multicenter Cervical Spondylotic Myelopathy International trial were included. Participants were approached for additional virtual assessment 10 years after surgery. Functional outcome was assessed according to the modified Japanese Orthopaedic Association (mJOA; scores 0-18) score at baseline and 1, 2, and 10 years after surgery. The minimal clinically important difference was defined as 1-, 2-, or 3-point improvement for mild, moderate, and severe myelopathy, respectively. Outcome was considered durable when stabilization or improvement after 2 years was maintained at 10 years. Self-evaluated effect of surgery was assessed using a 4-point Likert-like scale. Demographic, clinical, and surgical data were compared between groups that worsened and improved or remained stable using descriptive statistics. Functional outcome was compared between various time points during follow-up with linear mixed models.

RESULTS

Of the 42 originally included patients, 37 participated at follow-up (11.9% loss to follow-up, 100% response rate). The mean patient age was 56.1 years, and 42.9% of patients were female. Surgical approaches were anterior (76.2%), posterior (21.4%), or posterior with fusion (2.4%). The mean follow-up was 10.8 years (range 10-12 years). The mean mJOA score increased significantly from 13.1 (SD 2.3) at baseline to 14.2 (SD 3.3) at 10 years (p = 0.01). A minimal clinically important difference was achieved in 54.1%, and stabilization of functional status was maintained in 75.0% in the long term. Patients who worsened were older (median 63 vs 52 years, p < 0.01) and had more comorbidities (70.0% vs 25.9%, p < 0.01). A beneficial effect of surgery was self-reported by 78.3% of patients.

CONCLUSIONS

Surgical treatment for DCM results in satisfactory improvement of functional outcome that is maintained at 10-year follow-up.

Postoperative Kyphosis in Cervical Spondylotic Myelopathy: Cut-off Preoperative Angle for Predicting the Postlaminoplasty Kyphosis

STUDY DESIGN

A prospective cohort study.

OBJECTIVE

This study aimed to investigate the relationship between preoperative cervical sagittal alignment and postoperative kyphosis in patients with cervical spondylotic myelopathy (CSM) and to determine the cut-off angle for predicting the postlaminoplasty kyphosis.

SUMMARY OF BACKGROUND DATA

There have been several reports describing a cervical kyphosis after laminoplasty. However, there has been no study on the cut-off angle for predicting the postoperative kyphosis in a large series of patients with CSM.

METHODS

A total of 1025 consecutive patients with CSM (642 men and 383 women; mean age, 64.4 yr; range, 23-93 yrs) who underwent laminoplasty were included. The average follow-up period was 30.0 months. Radiography was performed before the surgery and at final follow-up. The cervical alignment with neutral view was measured by using the Cobb method. An alignment of C2-7 lordotic angle more than 0° was defined as lordosis and C2-7 lordotic angle less than 0° was defined as kyphosis. The incidence of postoperative kyphosis was evaluated on lateral radiographs.

RESULTS

In all patients, the mean C2-7 alignment in the neutral position was 11.5° lordotic before surgery and 14.2° lordotic at final follow-up. In the patient without preoperative kyphotic alignment, receiver operating characteristic curve of preoperative C2-7 lordotic angle showed 7° as a predictor for the postlaminoplasty kyphosis (area under the curve  = 0.75, P < 0.0001). Among the preoperatively 720 patients with lordosis more than 7°, postoperative kyphosis was observed in 20 patients (2.8%), whereas in the preoperatively 191 patients with lordosis less than 7°, postoperative kyphosis was seen in 28 patients (14.7%).

CONCLUSION

The cut-off value of preoperative C2-7 lordotic angle for predicting the postlaminoplasty kyphosis was 7° in CSM patient without preoperative kyphotic alignment.

LEVEL OF EVIDENCE

3.

Improved bone bonding of hydroxyapatite spacers with a high porosity in a quantitative computed tomography-image pixel analysis: A prospective 1-year comparative study of the consecutive cohort undergoing double-door cervical laminoplasty

Laminoplasty using hydroxyapatite (HA) spacers is widely performed in patients with cervical myelopathy. However, spacer dislocation is a critical complication caused by bone absorption and inadequate bone conductivity, and can result in dural damage and restenosis. We thus designed a prospective cohort study to clarify the feasibility of increased porosity HA spacers for double-door laminoplasty by analyzing computed tomography (CT) images. Forty-seven patients underwent cervical laminoplasty. Two different types of CERATITE HA spacer were used, either high porosity (50%) or low porosity (35%). These HA spacers were placed in an alternating manner into the laminae in each patient. In total, 85 high-porosity (50%) HA spacers and 84 low-porosity (35%) HA spacers were implanted. At postoperative 2 weeks, 3 months, 6 months, and 1 year, CT images were obtained. In both groups, the percentage of bone-bonding boundary area of the HA spacer in contact with laminae and bone volume of the spinous process relative to the 2-week value were calculated by a 3D and 2D CT-image pixel analysis. The bone-bonding ratio was significantly higher in high-porosity (50%) than low-porosity (35%) HA spacers at 3 months and thereafter (1 year, 69.3 ± 27.8% and 49.7 ± 32.9% respectively, P < .01). The bone volume in both groups significantly decreased with time (1 year, 73.2 ± 29.8% and 69.0 ± 30.4% respectively, P < .01), indicating bone absorption. This showed no significant difference between the HA spacers (P = .15) but was higher in high-porosity (50%) than low-porosity (35%) HA spacers throughout the study period. Meanwhile, spacer breakage was found in 4.7% of high-porosity (50%) HA spacers and 1.2% of low-porosity (35%) HA spacers (P = .37). In summary, high-porosity (50%) HA spacers have the advantages of accelerated bone bonding and relatively decelerated bone absorption compared to low-porosity (35%) HA spacers; however, possibly more frequent breakage of HA spacers with a high porosity (50%) requires careful, extended postoperative follow-up.

Motion Preservation at All Costs? Multilevel Hinge Nonunion, Plate Breakage, and Intradural Plate Migration After Cervical Laminoplasty: A Case Report and Literature Review

BACKGROUND

Cervical laminoplasty is a motion-preserving procedure that addresses spinal cord compression and avoids postlaminectomy kyphosis associated with cervical laminectomy. The most common complications include C5 nerve palsy, axial neck pain, hinge nonunion, and premature closure. Plating is a relatively newer method of laminoplasty fixation that may provide greater stabilization postoperatively and reduce the risk of laminoplasty closure compared with less rigid (e.g., suture) fixation techniques. Although prior studies have reported low rates of laminar/lateral mass screw back out, plate breakage and migration have not been previously described in the literature. The purpose of this paper is to present a case of multilevel hinge nonunion, plate breakage, and plate fragment migration. Although rare, plate failure may result in a dural tear and spinal cord injury/compression.

CASE DESCRIPTION

In this case, a 61-year-old man with a history of cervical spondylotic myelopathy treated with C3-7 laminoplasty 7 years prior presented to our hospital with severe headaches and electrical-type pain through the left upper and lower extremities. Imaging studies revealed several broken laminoplasty plates and intradural migration of a fragment of the C7 plate.

CONCLUSIONS

We provide recommendations for preventing hinge nonunion because resultant micromotion likely contributed to the plate breakages observed in this patient.

[All levels miniplate fixation and a modified hybrid fixation method in expansive open-door cervical laminoplasty: a retrospective comparative study]

OBJECTIVE

To retrospectively compare the effect of alternate levels miniplate and anchor fixation with the effect of all levels miniplate fixation in expansive open-door cervical laminoplasty (EOLP).

METHODS

Patients with cervical spondylosis underwent EOLP between July 2015 and June 2016 were included in the study. There were 33 patients in the alternate group (alternate levels miniplate and anchor fixation group) and 34 patients in the miniplate group (all levels miniplate fixation group). Neurological function was evaluated with the Japanese Orthopedic Association (JOA) score and degree of pain was assessed with the visual analogue scale (VAS) score. Basic clinical and surgical data, complication rates and medical costs of the two groups were compared. In addition, radiological examinations were performed pre- and post-operatively and at the final follow-up. Relative imaging data such as anteroposterior diameter (APD), cervical curvature index (CCI) and open angle were collected and compared.

RESULTS

(1) The mean follow-up time was 18.6 months in the alternate group and 18.9 months in the miniplate group. There were no significant differences in operation time, intraoperative blood loss, perioperative complication rates, post-operative hospital stays, VAS scores and neurological recovery rates preoperatively and at the final follow-up between the two groups. (2) Additionally, no obvious differences were observed about CCIs and APDs at the three follow-up time points between the two groups. Post-operative open angles at C4 and C6 in the alternate group were significantly smaller than those in the miniplate group. However, there were no significant differences in C3, C5 and C7 open angles between the two groups post-operatively. Notably, no significant differences were detected about the open angles at all levels between the two groups at the final follow-up. (3) When comparing radiologic data at different time points in each group, CCIs and open angles at each level had no significant differences, but APDs after surgery and at the final follow-up were significantly larger than pre-operative APDs. (4) Total costs in the alternate group were significantly lower than those in the miniplate group.

CONCLUSION

The two surgical methods showed almost the same neurological recovery rates and complication rates. However, use of alternate levels miniplate and anchor fixation in EOLP can reduce medical expenses.

Comparison of Health-related Quality of Life Between Double-door Laminoplasty and Selective Laminoplasty for Degenerative Cervical Myelopathy, With a Minimum Follow-up of 5 Years

STUDY DESIGN

A retrospective analysis of prospectively collected multicenter observational data.

OBJECTIVE

The aim of this study was to compare the health-related quality of life (HR-QOL) of double-door laminoplasty (DDL) and selective laminoplasty (SL) in patients with degenerative cervical myelopathy (DCM) in two institutions, with a minimum follow-up of 5 years.

SUMMARY OF BACKGROUND DATA

No study has compared DDL and SL regarding postoperative HR-QOL with a follow-up of more than 5 years.

METHODS

One-hundred ninety patients who underwent DDL (n = 77) or SL (n = 113) participated in this study. Short-form 36 (SF-36), Japanese Orthopedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), Neck Disability Index (NDI), and visual analog scale (VAS) values were compared between the groups.

RESULTS

Thirty-seven DDL and 52 SL patients were evaluated. The mean follow-up period was 8 years and the follow-up rate was 46.8%. No significant differences were found regarding age and JOA score at baseline. At the follow-up, there were no significant differences in SF-36, JOACMEQ, and VAS score, while the NDI score for headache and sleeping were higher in the SL group. After dividing the SL group into short and long SL subgroups, the long SL subgroup showed a significantly lower score in bodily pain in SF-36, lower and bladder function in JOACMEQ, and pain intensity, personal care, headaches, and sleeping in NDI compared with the other groups.

CONCLUSION

No significant differences were found in SF-36, JOA score, and NDI, except for the NDI subscale of headache and sleeping. The subgroup analysis showed that the long SL group showed a decreased QOL compared with the short SL and DDL groups.

LEVEL OF EVIDENCE

3.

Dural Laceration Resulting in the Formation of Syringomyelia Caused by a Loosened Hydroxyapatite Intraspinous Spacer after Spinous Process-splitting Laminoplasty

A 63-year-old man was admitted in our hospital with the chief complaint of upper limb numbness 3 years after undergoing spinous process-splitting laminoplasty (C3–C7) in another hospital. The hydroxyapatite spacers used for the laminoplasty had dislocated, resulting sensory disorders of the upper extremities. Additionally, loosened hydroxyapatite intraspinous spacers and syringomyelia were confirmed. A revision operation was performed, during which the C5 spacer was observed to have dislodged into the spinal canal, and a dural membrane defect, arachnoid membrane tear, cerebrospinal fluid leakage, and marked adhesion change were observed. The adhesion was exfoliated as far as possible; moreover, to prevent the reflux of syringomyelia, a syrinx-subarachnoid shunt (SS shunt) was placed. Although there was concern of further adhesion by putting foreign matter, SS shunt indwelling was chosen to obtain sure disappearance of syringomyelia. The postoperative course was uneventful. A gradual improvement in the upper limb numbness was observed without a recurrence of syringomyelia at 9 years of follow-up.

Postoperative neck symptoms of posterior approach for cervical compressive myelopathy: Expansive open-door laminoplasty vs. segmental partial laminectomy

BACKGROUND

Laminoplasty is widely accepted as a standard treatment of cervical compressive myelopathy. However, due to the risk of postoperative complications such as neck symptoms, segmental partial laminectomy (SPL) is performed instead, which results in fewer postoperative symptoms. The aim of this study was to describe the difference in the incidence and severity of postoperative neck symptoms between traditional C3-C7 expansive open-door laminoplasty (ELAP) and SPL.

METHODS

A retrospective and comparative study was performed regarding neck complications following the two surgical procedures. Twenty patients underwent SPL, and an additional 20 age- and gender-matched patients underwent traditional C3-C7 ELAP. Preoperative and postoperative JOA scores were measured, and postoperative neck symptoms in both groups were evaluated using a self-administered questionnaire, according to the Neck Pain and Disability Scale.

RESULTS

The total incidence of postoperative neck symptoms in the SPL group was similar to that in the ELAP group; however, the severity of symptoms was remarkably lower in the SPL group than in the ELAP group.

CONCLUSIONS

SPL seems to be a better procedure for reducing postoperative neck symptoms, when compared with C3-C7 ELAP.

Intradural extramedullary tumor in the stenotic cervical spine resected through open-door laminoplasty with hydroxyapatite spacers: report of two cases

Background

Safe excision of spinal cord tumors depends on sufficient visualization of the tumor and surrounding structures. In patients with spinal cord tumor adjacent to a stenotic spinal canal, extensive bony decompression proximal and distal to the tumor should be considered for safer excision of the tumor. Extensive wide laminectomy is one choice for such cases, but postoperative problems such as kyphotic deformity remain a concern.

Case presentation

A 76-year-old man and a 60-year-old woman presented with symptomatic intradural extramedullary spinal cord tumors in the cervical spine. Both patients showed a combination of spondylotic changes in the cervical spine and stenotic condition at the level of the tumor. Both tumors were successfully resected through open-door laminoplasty with hydroxyapatite (HA) spacers, with the tumor located on the side of the laminoplasty. Histological diagnosis was schwannoma for both tumors. HA spacers completely bonded to the host bone and did not interfere with postoperative magnetic resonance imaging (MRI) of the inside of the spinal canal. Cervical spine alignment was maintained at the final follow-up of 6 years in both cases.

Conclusion

Laminoplasty with HA spacers enabled successful tumor extirpation, reliable MRI follow-up after surgery, and maintenance of normal cervical spine alignment. Laminoplasty with HA spacers represents a good option for the treatment of cervical spinal cord tumor in patients combined with spinal stenosis.

Muscle-Preserving Selective Laminectomy Maintained the Compensatory Mechanism of Cervical Lordosis After Surgery

STUDY DESIGN

A retrospective single-center study.

OBJECTIVE

The aim of this study was to evaluate the compensatory mechanism of cervical lordosis (CL), the changes in cervical sagittal alignment, and range of motion (ROM) after muscle-preserving selective laminectomy (SL).

SUMMARY OF BACKGROUND DATA

CL increases as a compensatory mechanism for the adjustment of cervical sagittal balance or horizontal gaze. However, laminoplasty invades this mechanism and causes kyphosis in higher T1 (C7) slope patients.

METHODS

SL is a posterior surgery selecting the decompression laminae without disturbing the extensor musculature and facet joints. The clinical features and radiological findings of 125 cervical compressive myelopathy patients who underwent C6 single-level SL, C5-C6 two consecutive levels SL, C4-C6 three consecutive levels SL, and C3-C6 four consecutive levels SL were enrolled. Cervical spine lateral radiography was performed before surgery and at the final follow-up. The patients were divided into two groups according to the preoperative C7 slope. Postoperative cervical alignment change was compared between the higher and lower C7 slope groups. Subsequently, pre- and postoperative cervical alignment and cervical ROM were analyzed according to the number of consecutive laminae surgically treated.

RESULTS

Patients with higher C7 slope had greater lordotic cervical alignment and larger C2-C7 sagittal vertical axis (SVA) pre- and postoperatively. No kyphotic alignment change was observed, even in the higher C7 slope group. C6 SL and C5-C6 SL did not affect C2-C7 angle, and did not increase C2-C7 SVA after surgery. Although C4-C6 SL and C3-C6 SL demonstrated postoperative slight increase in C2-C7 SVA, C2-C7 angle never decreased after surgery. Cervical ROM slightly reduced in the C4-C6 SL and C3-C6 SL groups; however, no reduction of ROM was observed in the C6 SL and C5-C6 SL groups.

CONCLUSION

SL preserved the inherent compensatory CL that had been observed preoperatively and maintained cervical sagittal balance after surgery.

LEVEL OF EVIDENCE

4.

Predictors of Persistent Axial Neck Pain After Cervical Laminoplasty

STUDY DESIGN

Retrospective analysis of prospective data.

OBJECTIVE

The aim of this study was to reveal baseline predictors of persistent postlaminoplasty neck pain.

SUMMARY OF BACKGROUND DATA

Axial neck pain is one of the most common complications after cervical laminoplasty; however, baseline predictors of persistent postlaminoplasty neck pain are unclear.

METHODS

We analyzed data from 156 patients who completed a 2-year follow-up after double-door laminoplasty for degenerative cervical myelopathy. Patients rated the average intensity of axial neck pain in the last month using an 11-point numerical rating scale preoperatively and at the 2-year follow-up. The dependent variable was the presence of moderate-to-severe neck pain (numerical rating scale ≥4) at the 2-year follow-up. The independent variables included patient characteristics, baseline radiological parameters, surgical variables, baseline axial neck pain intensity, and baseline functions, which were measured by the Japanese Orthopaedic Association score and the Short Form-36 survey (SF-36). Logistic regression analysis was performed to identify independent predictors of moderate-to-severe neck pain after laminoplasty.

RESULTS

At the 2-year follow-up, 51 patients (32%) had moderate-to-severe neck pain, and 106 patients (68%) had no or mild pain. Univariate analysis revealed that the ratio of cervical anterolisthesis, ratio of current smoking, baseline neck pain intensity, and baseline SF-36 Mental Component Summary differed significantly between the groups. Multivariate logistic regression analysis showed that independent predictors of moderate-to-severe neck pain at the 2-year follow-up include the presence of anterolisthesis, current smoking, moderate-to-severe baseline neck pain, and lower SF-36 Mental Component Summary. The presence of anterolisthesis and moderate-to-severe baseline neck pain were also associated with significantly poorer physical function after surgery.

CONCLUSION

The presence of anterolisthesis was associated not only with the highest odds ratio of persistent neck pain but also with significantly poorer functional outcomes. Indications for cervical laminoplasty should be carefully determined in patients with cervical anterolisthesis.

LEVEL OF EVIDENCE

4.

Hemostatic function to regulate perioperative bleeding in patients undergoing spinal surgery: A prospective observational study

Although bleeding is a common complication of surgery, routine laboratory tests have been demonstrated to have a low ability to predict perioperative bleeding. Better understanding of hemostatic function during surgery would lead to identification of high-risk patients for bleeding. Here, we aimed to elucidate hemostatic mechanisms to determine perioperative bleeding. We prospectively enrolled 104 patients undergoing cervical spinal surgery without bleeding diathesis. Blood sampling was performed just before the operation. Volumes of perioperative blood loss were compared with the results of detailed laboratory tests assessing primary hemostasis, secondary hemostasis, and fibrinolysis. Platelet aggregations induced by several agonists correlated with each other, and only two latent factors determined inter-individual difference. Platelet aggregability independently determined perioperative bleeding. We also identified low levels of plasminogen-activator inhibitor-1 (PAI-1) and α2-plasmin inhibitor to be independent risk factors for intraoperative and postoperative bleeding, respectively. Most important independent factor to determine postoperative bleeding was body weight. Of note, obese patients with low levels of PAI-1 became high-risk patients for bleeding during surgery. Our data suggest that bleeding after surgical procedure may be influenced by inter-individual differences of hemostatic function including platelet function and fibrinolysis, even in the patients without bleeding diathesis.

Prevalence of complications after surgery in treatment for cervical compressive myelopathy: A meta-analysis for last decade

PURPOSE

We aim to perform a meta-analysis on prevalence of all kinds of operation-related complications following surgery treating cervical compressive myelopathy (CCM) and to provide reference for surgeons making surgical plan.

METHODS

An extensive search of literature was performed in PubMed/MEDLINE, Embase, the Cochrane library, CNKI, and WANFANG databases on incidence of operation-related complications from January 2007 to November 2016. Data was calculated and data analysis was conducted with STATA 12.0 and Revman 5.3.

RESULTS

A total of 107 studies included 1705 of 8612 patients (20.1%, 95% CI 17.3%-22.8%) on overall complications. The incidence of C5 plasy, cerebrospinal fluid (CSF), infection, axial pain, dysphagia, hoarseness, fusion failure, graft subsidence, graft dislodgment, and epidural hematoma is 5.3% (95% CI 4.3%-6.2%), 1.9% (95% CI 1.3%-2.4%), 2.8% (95% CI 1.7%-4.0%), 15.6% (95% CI 11.7%-19.5%), 16.8% (95% CI 13.6%-19.9%), 4.0% (95% CI 2.3%-5.7%), 2.6% (95% CI 0.2%-4.9%), 3.7% (95% CI 2.0%-5.5%), 3.4% (95% CI 2.0%-4.8%), 1.1% (95% CI 0.7%-1.5%), respectively. Patients with ossification of posterior longitudinal ligament (OPLL) (6.3%) had a higher prevalence of C5 plasy than those with cervical spondylotic myelopathy (CSM) (4.1%), and a similar trend in CSF (12.2% vs 0.9%). Individuals after laminectomy and fusion (LF) had highest rate of C5 plasy (15.2%), while those who underwent anterior cervical discectomy and fusion (ACDF) had the lowest prevalence (2.0%). Compared with patients after other surgical options, individuals after anterior cervical corpectomy and fusion (ACCF) have the highest rate of CSF (4.2%), infection (14.2%), and epidural hematoma (3.1%). Patients after ACDF (4.8%) had a higher prevalence of hoarseness than those with ACCF (3.0%), and a similar trend for dysphagia between anterior corpectomy combined with discectomy (ACCDF) and ACCF (16.8% vs 9.9%).

CONCLUSIONS

Based on our meta-analysis, patients with OPLL have a higher incidence of C5 palsy and CSF. Patients after LF have a higher incidence of C5 palsy, ACCDF have a higher incidence of dysphagia, ACCF have a higher incidence of CSF and infection and ACDF have a higher incidence of hoarseness. These figures may be useful in the estimation of the probability of complications following cervical surgery.

Smith-Robinson procedure with and without Caspar plating as a treatment for cervical spondylotic myelopathy: A 26-year follow-up of 23 patients

PURPOSE

The purpose of this study was to assess long-term follow-up data after anterior cervical decompression and fusion (ACDF) with and without Caspar plating (ACDF + PS) for the treatment of cervical spondylotic myelopathy (CSM) with special focus on functional outcome, pain, and repeat surgery for adjacent segment disease (ASD).

METHOD

Hospital records of 45 patients who were affected by CSM and underwent ACDF or ACDF + PS at least 17 years ago were reviewed. Information about diagnosis, surgical report, pre- and postoperative clinical process, and complications was analyzed. Clinical outcome was assessed using a standardized questionnaire including the Neck Disability Index (NDI), modified JOA-score, Odom's criteria, limitations in quality of life, and questions about the current neurological status and pain.

RESULTS

Twenty-three patients with a mean follow-up of 26 years were evaluated. ACDF was performed in nine and ACDF + PS in 14 patients, respectively. At follow-up 78.3% of patients were free of pain, 91.3% had no motor deficit, 73.9% had no sensory deficit, and 60.7% had no gait disturbance. The current mean NDI is 14% (range 2-44%), the mean modified JOA-score was 17.2 (range 15-18). According to Odom's criteria 78.3% of patients had clinical success. In four patients repeat surgery was indicated due to pseudarthrosis or symptomatic ASD (17.4%).

CONCLUSIONS

ACDF and ACDF + PS yield significant decrease in neck pain, a significant increase in sensorimotor function and a high rate of clinical success. Patients with preoperative gait disturbance completely recovered in about 60% of cases. Overall prevalence for ASD was 17.4% after 25 years.

A Comparison of Implants Used in Double Door Laminoplasty : Allogeneic Bone Spacer versus Hydroxyapatite Spacer

Objective

The aim of this study was to compare the clinical and radiological outcomes associated with the use of hydroxyapatite (HA) spacer and allogeneic bone (AB) spacer in laminoplasty.

Methods

From January 2006 to July 2014, 79 patients with cervical spondylotic myelopathy or ossification of the posterior longitudinal ligament underwent cervical laminoplasty. The radiologic parameters were obtained from plain radiography and three-dimensional computed tomography. All images were taken before and after surgery. Cervical lordosis, spinal canal dimension, fusion between lamina and spacer, and resorption of spacer were checked. Clinical outcomes were assessed using visual analog scale and Japanese Orthopedic Association.

Results

Double-door laminoplasty was performed on 280 levels : 182 in the HA group and 98 in the AB group. The mean follow-up was 23.1 months (range : 4–69 months). Similar fusion rates were found in these groups (p=0.3). The resorption rate between lamina and spacer was lower in the HA group (p<0.001). During the immediate postoperative period, the canal dimension of both groups increased compared with the results in the preoperative period. However, the canal dimension of the AB group decreased over time compared with that of the HA group (p<0.001).

Conclusion

Double-door laminoplasty improved the clinical outcomes of both groups. However, the spinal canal dimension in the AB group showed a greater degree of reduction than in the HA group at the final postoperative follow-up. Therefore, we suggest that surgeons consider the use of larger-sized AB spacers in double-door laminoplasties.

More Than 20 Years Follow-up After En Bloc Cervical Laminoplasty

STUDY DESIGN

Retrospective study.

OBJECTIVE

The aim of the study was to evaluate clinical outcomes and to clarify the potential risks of cervical laminoplasty by a long-term follow-up of more than 20 years.

SUMMARY OF BACKGROUND DATA

There is no follow-up report exceeding 20 years after cervical laminoplasty.

METHODS

Two hundred sixteen patients underwent en bloc cervical laminoplasty for the treatment of cervical compressive myelopathy due to cervical spondylosis or ossification of the posterior longitudinal ligament between 1981 and 1994. Of these, 148 patients with a follow-up of more than 20 years were retrospectively studied (68 survived patients and 80 dead patients). The neurological evaluation was graded using Japanese Orthopaedic Association (JOA) score and the recovery rate. Neurological recovery was defined by the increase in JOA score. Radiological examinations were carried out using pre- and postoperative radiographs. As for the dead patients, the cause and age of death were reviewed.

RESULTS

The JOA score and recovery rate increased to 14.2 ± 2.7% and 64.9 ± 28.6%, respectively, at 5 years. The JOA score and recovery rate were maintained at 13.9 ± 3.2% and 61.6 ± 34.6% at 10 years. The JOA score decreased to 11.4 ± 5.1 at the last follow-up. In 32 out of 65 patients (49.2%), the JOA scores worsened mainly due to other spinal lesions. Cervical alignment became kyphotic when comparing preoperatively and at the last follow-up (ossification of the posterior longitudinal ligament: 15.7 ± 12.2° and 6.9 ± 17.8°, cervical spondylosis: 11.0 ± 8.9° and 3.3 ± 9.4°). Range of motion (ROM) decreased and one of the causes of ROM reduction was interlaminar fusion. The mean age at death was 78.2 years. The most frequent cause of death was malignant tumor.

CONCLUSION

Spine surgeons must be aware that patients have a long postoperative lifetime when cervical laminoplasty is performed. A long postoperative follow-up should be carried out after laminoplasty.

LEVEL OF EVIDENCE

4.

Intrathecal morphine for postoperative pain control after laminoplasty in patients with cervical spondylotic myelopathy

OBJECTIVES

To examine the clinical efficacy of intrathecal morphine as postoperative analgesia for cervical laminoplasty.

SUMMARY OF BACKGROUND DATA

Patients who undergo posterior cervical spinal surgery frequently experience significant postoperative pain. Postoperative pain contributes to patient morbidity because of decreasing early voluntary mobilization and delayed rehabilitation. Intrathecal morphine is known to be a simple and effective analgesia. However, the effectiveness of intrathecal morphine for cervical spinal surgery has not yet been reported.

METHODS

Seventy-eight patients with cervical spondylotic myelopathy were divided into two groups prospectively, a diclofenac suppository (DS) group who received 50 mg diclofenac suppository at the end of the surgery, and an intrathecal morphine (ITM) group who were preoperatively administered 0.3 mg of morphine chloride, intrathecally, via a lumbar puncture. All patients underwent double-door laminoplasty of C3-6 or C3-7 level. Visual analog scale (VAS) of cervical pain, self-rating pain impression, supplemental analgesic usage, and complication rate were evaluated until the seventh postoperative day.

RESULTS

Thirty-one patients in the DS group and 32 patients in the ITM group were finally assessed. No baseline variable differences between the two groups were observed. The VAS was significantly lower in the ITM group at 4 h and 24 h until the seventh postoperative day. Self-rating pain impression was significantly better in the ITM group. No significant difference was observed in complication rate.

CONCLUSIONS

Intrathecal morphine was an effective and safe analgesic method for cervical laminoplasty in patients with cervical spondylotic myelopathy.

CERVICAL SPINOLAMINOPLASTY WITH NEWLY DESIGNED TITANIUM MINI-PLATES

One of the complication of cervical laminoplasty is the restenosis of the opened laminae. Weakness of the screws placed on laminae may cause restenosis. Here, we describe a new technic ‘spinolaminoplasty (Turkish Open-door laminoplasty)’ with newly designed titanium mini plate that placed one side to lateral mass, and the other on spinous process to keep the laminae opened. Two different fixation materials were used for axial compression tests. One was Ultra high molecular weight polyethylene block with cervical vertebrae geometry and fresh ovine cervical vertebrae. In the first group, mini plates were fixed on laminae as in the conventional method described by Hirabayashi. In the second group, mini plates were fixed on spinous process to perform spinolaminoplasty with single and double screws. New fixation method with double screw provides 26% higher stiffness than the closest group, namely new fixation on polyethylene block. And new fixation method with double screw was exhibited significantly higher ([Formula: see text]) performance between the Ovine groups. As in the spinolaminoplasty technic fixing the mini plates to spinous process with longer screws instead of laminae, strengthens the system compared to the conventional method. This proves that rigidity of new construction model is more stable than the conventional method. Tight fixed laminae may prevent restenosis. Also applying the screw through spinous process instead of laminae may prevent the possible cord injuries.

Can Modified Kurokawa's Double-Door Laminoplasty Reduce the Incidence of Axial Symptoms at Long-term Follow-up?: A Prospective Study of 152 Patients With Cervical Spondylotic Myelopathy

STUDY DESIGN

A prospective cohort study.

OBJECTIVE

The purpose of this study was to determine whether the modified procedure reduces long-term axial symptoms (AS) and to understand better why the AS occur.

SUMMARY OF BACKGROUND DATA

Following Kurokawa's double-door laminoplasty, postoperative AS reduce the quality of life of patients with cervical spondylotic myelopathy. The etiology of AS remains unclear. Some studies report that preservation of the C7 spinous process can reduce the frequency of AS. The modified Kurokawa procedure prevents AS by preserving the semispinalis cervicis insertion in the spinous process of C2. However, it remains unclear whether the modified procedure lowers the incidence of AS in the long term (ie, >3 y).

MATERIALS AND METHODS

This prospective cohort study investigated preoperative and postoperative v, cervical intervertebral range of motion, postoperative neurological recovery, neck disability index, visual analog scale, surgical cost, and time and blood loss.

RESULTS

Both groups had satisfied improvement of neurological functions (P>0.05). At 3 months and 1 year after surgery, the difference in frequency between no symptoms and mild/severe symptoms was significant (traditional group, 39.06%; modified group, 20.45%) (P<0.05). Interestingly, 3 years after surgery, there were no significant between-group differences (P>0.05).

CONCLUSIONS

This modified approach reduced the incidence of postoperative ASs at 3 months and 1 year after the operation; however, the between-group difference was not significantly different at the 3-year follow-up. The reason for this finding is unclear; it may indicate that the incidence of AS is caused by other factors, such as the preservation of the C7 spinous process rather than the C2 spinous process.

Impact of Axial Neck Pain on Quality of Life After Laminoplasty

STUDY DESIGN

A prospective study.

OBJECTIVE

The aim of this study was to elucidate the impact of axial pain following cervical laminoplasty on health-related quality of life (HRQOL).

SUMMARY OF BACKGROUND DATA

Axial neck pain is a frequently encountered complication after laminoplasty. However, limited information is available regarding the time-dependent changes in axial pain and the impact of this pain on clinical outcomes, including HRQOL.

METHODS

One hundred sixty-two consecutive patients with cervical myelopathy underwent double-door laminoplasty using hydroxyapatite spacers from 2008 to 2012. The outcome measures included the Japanese Orthopaedic Association score (JOA score), the EuroQol 5 Dimension Questionnaire (EQ-5D), and the Short Form-36 survey (SF-36). The intensity of axial pain was assessed using an 11-point numerical rating scale (NRS). These assessments were conducted preoperatively and at 6-month, 1-year, and 2-year follow-ups. Patient satisfaction with outcome was graded using a 7-point NRS at the 2-year follow-up.

RESULT

One hundred twenty-one patients completed the 2-year follow-up. The mean axial pain intensity decreased slightly over time; however, the decrease was not significant. The JOA score, EQ-5D score, and all SF-36 domains, excluding general health perceptions, improved significantly compared with baseline levels at the 6-month follow-up or later. Baseline axial pain intensity showed a significant negative correlation with baseline HRQOL only in the SF-36 bodily pain domain. In contrast, axial pain intensity showed significant negative correlations with all HRQOL measures at the 6-month follow-up. At the 2-year follow-up, patients with an axial pain intensity ≥3 showed significantly worse outcomes than did patients with a pain intensity <3 in the EQ-5D score, SF-36 score, and patient satisfaction grades, but not in the JOA score.

CONCLUSION

Axial neck pain has a significant negative impact on clinical outcomes, including a wide range of HRQOL measures and patient satisfaction with outcome, in patients undergoing conventional double-door laminoplasty.

LEVEL OF EVIDENCE

3.

Cervical Laminoplasty: The History and the Future

Cervical laminoplasty was developed as an alternative to cervical laminectomy for treatment of cervical myelopathy, in which hinges are created to lift the lamina. Various techniques of laminoplasty have since been developed after two prototype techniques: Hirabayashi’s open-door laminoplasty and Kurokawa’s spinous process splitting (double-door) laminoplasty. Several in vitro studies report superior biomechanical stability of the cervical spine after laminoplasty compared with laminectomy. In clinical situation, randomized control studies are scarce and superiority of one procedure over another is not uniformly shown. Lack of hard evidence supporting the purported advantages of laminoplasty over laminectomy, that is, reduced rate of postoperative instability and kyphosis development, while preserving range of motion (ROM), has been a weak selling point. Currently, laminoplasty is performed by majority of spine surgeons in Japan, but is rarely performed in the United States and Europe. Recent development in laminoplasty is preservation of muscle attachment, which enabled dynamic stabilization of the cervical spine by neck extensor muscles. After treatment with new laminoplasty techniques with active postoperative neck ROM exercises, postoperative instability, kyphosis, axial neck pain, and loss of ROM seems minimal. Well-designed clinical trials to show the effectiveness and long-term outcome of this surgical procedure are warranted.

Cervical laminoplasty developments and trends, 2003-2013: a systematic review

OBJECT

Despite extensive clinical experience with laminoplasty, the efficacy of the procedure and its advantages over laminectomy remain unclear. Specific clinical elements, such as incidence or progression of kyphosis, incidence of axial neck pain, postoperative cervical range of motion, and incidence of postoperative C-5 palsies, are of concern. The authors sought to comprehensively review the laminoplasty literature over the past 10 years while focusing on these clinical elements.

METHODS

The authors conducted a literature search of articles in the Medline database published between 2003 and 2013, in which the terms "laminoplasty," "laminectomy," and "posterior cervical spine procedures" were used as key words. Included was every single case series in which patient outcomes after a laminoplasty procedure were reported. Excluded were studies that did not report on at least one of the above-mentioned items.

RESULTS

A total of 103 studies, the results of which contained at least 1 of the prespecified outcome variables, were identified. These studies reported 130 patient groups comprising 8949 patients. There were 3 prospective randomized studies, 1 prospective nonrandomized alternating study, 15 prospective nonrandomized data collections, and 84 retrospective reviews. The review revealed a trend for the use of miniplates or hydroxyapatite spacers on the open side in Hirabayashi-type laminoplasty or on the open side in a Kurokawa-type laminoplasty. Japanese Orthopaedic Association (JOA) scoring was reported most commonly; in the 4949 patients for whom a JOA score was reported, there was improvement from a mean (± SD) score of 9.91 (± 1.65) to a score of 13.68 (± 1.05) after a mean follow-up of 44.18 months (± 35.1 months). The mean preoperative and postoperative C2-7 angles (available for 2470 patients) remained stable from 14.17° (± 0.19°) to 13.98° (± 0.19°) of lordosis (average follow-up 39 months). The authors found significantly decreased kyphosis when muscle/posterior element-sparing techniques were used (p = 0.02). The use of hardware in the form of hydroxyapatite spacers or miniplates did not influence the progression of deformity (p = 0.889). An overall mean (calculated from 2390 patients) of 47.3% loss of range of motion was reported. For the studies that used a visual analog scale score (totaling 986 patients), the mean (cohort size-adjusted) postoperative pain level at a mean follow-up of 29 months was 2.78. For the studies that used percentages of patients who complained of postoperative axial neck pain (totaling 1249 patients), the mean patient number-adjusted percentage was 30% at a mean follow-up of 51 months. The authors found that 16% of the studies that were published in the last 10 years reported a C-5 palsy rate of more than 10% (534 patients), 41% of the studies reported a rate of 5%-10% (n = 1006), 23% of the studies reported a rate of 1%-5% (n = 857), and 12.5% reported a rate of 0% (n = 168).

CONCLUSIONS

Laminoplasty remains a valid option for decompression of the spinal cord. An understanding of the importance of the muscle-ligament complex, plus the introduction of hardware, has led to progress in this type of surgery. Reporting of outcome metrics remains variable, which makes comparisons among the techniques difficult.

Essential Surgical Technique for French-Door (Double-Door) Laminoplasty

Introduction

We describe the surgical technique and the pitfalls of French-door laminoplasty.

Step 1: Patient Positioning

Position the patient to keep the cervical spine “parallel to the floor” or in the “reverse Trendelenburg position” with only a slight incline and place intraoperative neurological monitors to prevent intraoperative neurological deterioration.

Step 2: Surgical Approach

Use the common cervical posterior approach to expose the lamina and ligamentum flavum.

Step 3: Create Grooves

Cut the center of each lamina and create bilateral grooves using a high-speed burr.

Step 4: Open the Lamina

Open the lamina bilaterally and create a small hole in each one using a high-speed burr.

Step 5: Create Bone Struts

Create bone struts from the spinous processes and tie them to each lamina.

Step 6: Wound Closure

Perform meticulous closure of the wound to avoid wound-healing complications.

Results

In our original study¹², we treated forty-six patients with French-door laminoplasty and compared the surgical results of this procedure with those of open-door laminoplasty in a prospective, randomized controlled manner.

Indications

Contraindications

Pitfalls & Challenges

Patient satisfaction with double-door laminoplasty for cervical compression myelopathy

BACKGROUND

Patient satisfaction with posterior laminoplasty for cervical compression myelopathy is not yet established. Moreover, postoperative patient-reported outcomes (PROs) associated with patient satisfaction remain unclear. This study aimed to investigate patient satisfaction after double-door laminoplasty for cervical compression myelopathy, and to identify the postoperative patient-reported outcomes associated with patient satisfaction.

METHODS

This retrospective study included 97 patients with cervical compression myelopathy who underwent double-door laminoplasty between 2002 and 2010 in our institution [mean follow-up: 58 months (range 12-123 months)]. We assessed postoperative PROs from questionnaires administered before surgery and at the latest follow-up. These questionnaires included the Neck Disability Index, physical and mental component summary of Short Form-36, EuroQol-5 dimension, Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), and a numerical rating scale of pain or numbness in the neck, arms, and scapular lesion. Satisfaction was evaluated on the basis of a seven-point scale. Patients were divided into two groups: satisfied (very satisfied, satisfied, slightly satisfied) and dissatisfied (neither satisfied nor dissatisfied, slightly dissatisfied, dissatisfied, very dissatisfied). All PROs and the effectiveness of surgical treatment assessed by JOACMEQ were compared between both groups.

RESULTS

The satisfied group comprised 69 patients (71 %). Univariate analysis revealed a significant difference in scapular pain, Neck Disability Index, physical component summary of Short Form-36, postoperative mental component summary of Short Form-36, and improvement of lower extremity function postoperatively between both groups. Multivariate analysis revealed that there was a significantly higher proportion of patients with improved lower extremity function in the satisfied group than in the dissatisfied group.

CONCLUSIONS

In conclusion, 71 % of the patients who underwent double-door laminoplasty for cervical compression myelopathy were satisfied. The findings of this study, which examines the association between patient satisfaction and PROs, suggest that improvement in lower extremity function following surgical intervention affects patient satisfaction in those with cervical compression myelopathy.

Open-door versus French-door laminoplasty for the treatment of cervical multilevel compressive myelopathy

Open-door laminoplasty (ODL) and French-door laminoplasty (FDL) are used to treat cervical multilevel compressive myelopathy. However, differences in outcome between the approaches remain unknown. To investigate treatment differences, we performed a systematic review and meta-analysis. Four comparative trials were identified and analyzed in the review. The results showed that ODL had a higher postoperative Japanese Orthopaedic Association (JOA) score than FDL (weighted mean difference [WMD]=0.83; 95% confidence interval [CI]: 0.47 to 1.19; p<0.01). There were no significant differences between the two methods in terms of operative time (WMD=-6.76; 95% CI: -21.70 to 8.18; p=0.38), intraoperative blood loss (WMD=41.70; 95% CI: -61.43 to 144.82; p=0.43), total complication rate (OR=2.43, 95% CI: 0.22 to 27.04; p=0.47), postoperative C5 palsy (OR=1.97, 95% CI: 0.46 to 8.39; p=0.36), postoperative cervical lordosis (WMD=-0.60; 95% CI: -0.37 to 1.86; p=0.63) or range of motion (WMD=-4.62; 95% CI: -13.06 to 3.82; p=0.28). These results suggest that neither cervical laminoplasty approach is superior to the other based on the postoperative radiological data and complication rate, although ODL had higher postoperative JOA score than FDL.

The relationship between laminoplasty opening angle and increased sagittal canal diameter and the prediction of spinal canal expansion following double-door cervical laminoplasty

PURPOSE

To clarify the relationship between laminoplasty opening angle (LOA) and the increase in sagittal canal diameter (SCD) in double-door cervical laminoplasty (DDCL) and to predict the increase in SCD using the resulting formula.

METHODS

We analyzed 20 patients with multilevel cervical spondylotic myelopathy who underwent DDCL between September 2010 and January 2013. The pre- and post-operative parameters of the cervical spinal canal were measured by computed tomography. We deduced a formula describing the relationship between LOA and the increase in SCD and used it to predict the increase in SCD of these patients as LOA increased.

RESULTS

When the C3-C7 LOA was 25°-45°, the magnitude of the increase in SCD was notable (increases of 3.08-5.6 mm compared with the pre-operative SCD). When the C3-C7 LOA was more than 45°, the magnitude of the increase in SCD was relatively smaller; the increase in C3-C7 SCD with a 55° LOA was merely 0.4 mm more than with a 45° LOA. When LOA was 30° at C3-C6 or 40° at C7, the increase in SCD was more than 4 mm. When the C3-C6 LOA was 40°, SCD increased by more than 5 mm.

CONCLUSIONS

The formula accurately showed the relationship between LOA and the increase in SCD in DDCL. Based on the LOA, increases in SCD following C3-C7 laminoplasty can be accurately predicted using this formula. This enables DDCL based on accurate individual LOAs, which prevents inadequate or excessive opening.

Preoperative predictors of patient satisfaction with outcome after cervical laminoplasty

Study design Prospective cohort study. Objective The purpose of the present study was to identify the predictors of patient satisfaction with outcome after cervical laminoplasty for compressive cervical myelopathy. Methods A cohort of 143 patients with compressive myelopathy who underwent cervical double-door laminoplasty between 2008 and 2011 was studied prospectively. The principal outcome was patient satisfaction with outcome at 1 year after surgery. Patient satisfaction was graded on an ordinal scale from 1 to 7. Subjective health-related quality of life (QOL) and objective disease-specific outcome was measured by Short Form-36 (SF-36) and the Japanese Orthopaedic Association (JOA) score, respectively, before surgery and at 1-year follow-up. We evaluated the association between patient satisfaction at 1-year follow-up and various baseline parameters, including patient demographics, duration of symptoms, comorbidities, imaging findings, JOA score, and SF-36 scores. Results A total of 116 patients completed subjective and objective follow-up for a minimum of 1 year. Of 116 patients, 95 patients (81.9%) were satisfied with the outcome ("satisfied a little" or more). The unsatisfied group ("neutral" or less) showed significantly lower baseline SF-36 scores in bodily pain (BP), general health perceptions (GH), and vitality (VT) domains compared with the satisfied group. At the 1-year follow-up, SF-36 scores showed significant differences between the groups in all eight domains, whereas the JOA score showed no significant difference. Conclusions Lower baseline QOL measured by SF-36 scores, specifically in BP, GH, and VT domains, are associated with lower satisfaction with outcome after cervical laminoplasty.

Morphological characteristics of cervical spine in patients with athetoid cerebral palsy and the accuracy of pedicle screw placement

STUDY DESIGN

A retrospective study.

OBJECTIVE

To investigate the morphology of the cervical spine in patients with athetoid cerebral palsy (CP), and to evaluate its relationship with the breach of cervical pedicle screws.

SUMMARY OF BACKGROUND DATA

Cervical pedicle screws have been increasingly used in surgery for patients with CP, but screw misplacement is not uncommon. Although the altered morphology of the cervical spine in patients with CP may result in this high breach rate, few studies have examined the cervical pedicle profile.

METHODS

We retrospectively analyzed 31 patients with cervical myelopathy with CP, as well as 30 patients with cervical spondylotic myelopathy (CSM), who underwent posterior decompression surgery. The pedicle outer diameter, inner diameter, transverse angle and lateral mass deformity were investigated by obtaining preoperative computed tomographic scans. The accuracy of the placement of 56 pedicle screws used in fusion surgery for 12 patients with CP was also analyzed using postoperative computed tomographic scans.

RESULTS

The outer diameter of the pedicle in CP was in the range from 3.3 to 9.6 mm, and was larger than that in CSM at all cervical levels except for C7. Pedicle sclerosis was more frequently observed in CP than in CSM (23% vs. 7.3%, P < 0.001). The transverse angle at C3 and C4 was larger, and lateral mass deformity was more frequently observed in CP than in CSM. The critical breach of pedicle screws in CP was found in 29%. A multivariate analysis revealed that pedicle sclerosis was associated with an increased risk of breach (odds ratio: 6.3; 95% confidence interval: 1.03-39.0; P = 0.047).

CONCLUSION

The pedicle diameter in patients with CP was relatively large, but pedicle sclerosis, a wide transverse angle and lateral mass deformity were frequently observed. Sclerotic pedicles were associated with a higher risk of critical breach.

LEVEL OF EVIDENCE

N/A.

Localization of the medial branches of the cervical dorsal rami during cervical laminoplasty

STUDY DESIGN

Observational anatomic study.

OBJECTIVE

To give precise information on the surgical anatomy of the medial branches of the cervical dorsal rami.

SUMMARY OF BACKGROUND DATA

The anatomy of the medial branches has not been sufficiently described.

METHODS

We recorded the location of the medial branches in 94 consecutive patients who underwent laminoplasty for cervical compression myelopathy. A posterior cervical approach was made along the edge of the nuchal ligament, and, after carefully detaching the trapezius muscle from the nuchal ligament; we identified the right-side branches around the semispinalis capitis muscle. We recorded the location of the branches with reference to the spinous processes and the semispinalis capitis and trapezius muscles. In 52 patients, we electrically stimulated the branches and observed the contraction of these muscles.

RESULTS

Branches were identified between C3 and C6 spinous process levels in 92 patients. A single branch was identified in 56 patients, 2 branches were identified in 35 patients, and 3 branches were identified in the remaining 1 patient. Branches were located between C3 and C4 (n = 12), between C4 and C5 (n = 80), between C5 and C6 (n = 2), and at C6 (n = 35). There were 4 patterns of final course: 52 branches passed through the medial side of the semispinalis capitis and trapezius muscles and terminated in a subcutaneous area; 50 branches penetrated the semispinalis capitis and trapezius muscles and terminated in a subcutaneous area; 12 branches terminated in the semispinalis capitis muscle; and 15 branches penetrated the semispinalis capitis and terminated at the nuchal ligament. In 19 of 52 patients tested, the semispinalis capitis muscle contracted after electrical stimulation.

CONCLUSION

Medial branches of the cervical dorsal rami were discernible in cervical posterior approach laminoplasty and were frequently found adjacent to C4 and C5 spinous processes. The medial branches sometimes supplied motor fibers to the semispinalis capitis muscle. Knowledge of the course of these branches might be helpful for avoiding injury during laminoplasty.

Midline-Splitting Open Door Laminoplasty Using Hydroxyapatite Spacers : Comparison between Two Different Shaped Spacers

Objective

Although hydroxyapatite (HA) spacer has been used for laminoplasty, there have been no reports on factors associated with fusion and on the effects of HA shape.

Methods

During January 2004 and January 2010, 45 patients with compressive cervical myelopathy underwent midline-splitting open door laminoplasty with winged (33 cases) and wingless (12 cases) HAs by a single surgeon. Minimal and mean follow up times were 12 and 28.1 months, respectively. Japanese Orthopedic Association (JOA) score was used for clinical outcome measurement. Cervical X-rays were taken preoperatively, immediately post-operatively, and after 3, 6, and 12 months and computed tomography scans were performed preoperatively, immediately post-operatively and after 12 months. Cervical lordosis, canal dimension, fusion between lamina and HA, and affecting factors of fusion were analyzed.

Results

All surgeries were performed on 142 levels, 99 in the winged and 43 in the wingless HA groups. JOA scores of the winged group changed from 10.4±2.94 to 13.3±2.35 and scores of the wingless group changed from 10.8±2.87 to 13.8±3.05. There was no significant difference on lordotic and canal dimensional change between two groups. Post-operative 12 month fusion rate between lamina and HA was significantly lower in the winged group (18.2 vs. 48.8% p=0.001). Multivariate analysis showed that ossification of the posterior longitudinal ligament, male gender, and wingless type HA were significantly associated with fusion.

Conclusion

Clinical outcome was similar in patients receiving winged and wingless HA, but the wingless type was associated with a higher rate of fusion between HA and lamina at 12 months post-operatively.

Cervical alignment and range of motion after laminoplasty: radiographical data from more than 500 cases with cervical spondylotic myelopathy and a review of the literature

STUDY DESIGN

A large-scale analysis of radiographical results of patients with cervical spondylotic myelopathy and a review of the literature.

OBJECTIVE

To identify changes in sagittal alignment and range of motion (ROM) after cervical laminoplasty.

SUMMARY OF BACKGROUND DATA

Cervical laminoplasty is an effective procedure for decompressing multilevel spinal cord compression. It often induces postoperative complications such as loss of lordotic alignment and restriction of neck motion. Although numerous studies have reported the loss of flexion-extension ROM after laminoplasty, no large-scale study has been reported.

METHODS

Five hundred twenty consecutive patients with cervical spondylotic myelopathy (331 male and 189 female; mean age, 62.2 yr) who underwent modified double-door laminoplasty were enrolled. The average follow-up period was 33.3 months. All patients were allowed to sit up and walk on the first postoperative day using an orthosis, which could be removed within the first 2 weeks, even if long. Early cervical ROM exercises were performed as a part of the rehabilitation schedule. Radiography was performed before surgery and at the final follow-up. Cervical alignment in the neutral and flexion-extension view were measured by the Cobb method at C2-C7. The ROM was assessed by measuring the difference in alignment between flexion and extension.

RESULTS

The mean C2-C7 alignment in the neutral position was 11.9° lordotic preoperatively and 13.6° lordotic postoperatively; the alignment increased by 1.8° in lordosis. The mean total ROM decreased from a preoperative value of 40.1° to 33.5° at the final follow-up, showing a significant difference of 6.6°. The mean total ROM preservation after laminoplasty was 87.9%.

CONCLUSION

Sagittal alignment was slightly changed, with only a 1.8° increase in lordosis. The ROM of the cervical spine was preserved by 87.9%. This preservation of alignment and ROM might be attributable to improvements including early removal of the cervical orthosis, postoperative neck exercises, and some surgical modifications.

Ultrasonographic quantification of spinal cord and dural pulsations during cervical laminoplasty in patients with compressive myelopathy

PURPOSE

Pulsatile movements of the dura mater have been interpreted as a sign that the cord is free within the subarachnoid space, with no extrinsic compression. However, the association between restoration of pulsation and adequate decompression of the spinal cord has not been established. The present study investigated the relationship between the extent of spinal cord decompression and spinal cord and dural pulsations based on quantitative analysis of intraoperative ultrasonography (US).

METHODS

Eighty-five consecutive patients (55 males, 30 females; mean age, 64 ± 13 years) who underwent cervical double-door laminoplasty to relieve compressive myelopathy were enrolled. Spinal cord decompression status was classified as: Type 1 (non-contact), the subarachnoid space was retained on the ventral side of the cord, Type 2 (contact and apart), the cord showed both contact with and separation from the anterior element of the cervical spine, or Type 3 (contact), the cord showed continuous contact with the anterior element of the cervical spine. Spinal cord and dura mater dynamics were quantitatively analyzed using automatic video-tracking software. Furthermore, the intensity of spinal and dural pulsation was compared with the recovery of motor function at 1 year after surgery as measured by increase in the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ).

RESULTS

Spinal cord pulsation amplitude ranged from 0.01 to 0.84 mm (mean 0.30 ± 0.16 mm) and dural pulsation amplitude ranged from 0.01 to 0.38 mm (mean 0.14 ± 0.08 mm). Average spinal cord pulsation amplitude in Type 2 patients was significantly larger than that in the other groups, whereas, average dural pulsation amplitudes were similar for all three groups. There was a significant correlation between spinal cord and dural pulsation amplitudes in Type 1 patients, but not in Type 2 or Type 3 patients. Type 3 patients showed a particularly poor correlation between spinal cord and dural pulsations. Spinal cord pulsation amplitude was moderately correlated with the recovery of motor function evaluated by JOACMEQ.

CONCLUSION

The present results suggest that restoration of dural pulsation is not an adequate indicator of sufficient decompression of the spinal cord following a surgical procedure.

Clinical results of and patient satisfaction with cervical laminoplasty for considerable cord compression with only slight myelopathy

PURPOSE

There is no established consensus on the indications for surgery in patients with considerable cord compression but only slight myelopathy. The purpose of this study is to stimulate discussion about the indications for surgery in these patients.

METHODS

The records of consecutive patients who underwent cervical laminoplasty (CLP) during 3.5 years were reviewed. Those patients whose pre-operative Japanese Orthopaedic Association score (JOA score, maximum 17) for cervical myelopathy was 16 points or more, indicating that they had very slight myelopathy, were selected. The postoperative JOA scores of these patients were checked via a chart review, and they were sent a survey asking about their degree of satisfaction with the results of surgery.

RESULTS

Of 143 patients who underwent CLP, 14 presented with a preoperative JOA score of 16 or more. No patients showed a postoperative deterioration in JOA score. Nine patients complained of pre-operative hand numbness and this symptom disappeared postoperatively in seven cases. Most patients were satisfied with the results of the surgery: "very satisfied" in 11 cases and none selected "slightly dissatisfied" or "very dissatisfied".

CONCLUSIONS

We believe that surgery can rescue well-informed and deliberately selected patients with only slight myelopathy, because their symptoms improve and they are freed from persistent anxiety.