Expansive Open-door Laminoplasty Research Articles

Impact of different laminae open angles on axial symptoms after expansive open-door laminoplasty.

The present study is a retrospective study.Axial symptoms are frequently encountered complication after laminoplasty. Some studies have reported the influencing factors and preventive measures of axial symptoms after laminoplasty. However, impact of different laminae open angles on the postoperative axial symptoms remains unclear.The objective of the present study was to explore the effect of different laminae open angles on postoperative axial symptoms and to discuss the possible mechanisms of the impact of different open angles on axial symptoms.We retrospectively analyzed 124 patients with multilevel cervical compression myelopathy who were treated with expansive open-door laminoplasty from February 2012 to January 2015. The operational level ranged from C3-C7 in all patients. The laminae open angles at the C4, C5, and C6 levels were measured 1 week postoperative. The mean value was taken for statistical analysis. The patients were divided into 2 groups, group A (open angles < 40°, 71 patients including 44 males and 27 females) and group B (open angles ≥ 40°, 53 patients including 32 males and 21 females). C2-C7 Cobb angle, range of cervical motion (ROM), Japanese Orthopedic Association (JOA) score, and visual analog scale (VAS) score for axial pain were compared between the 2 groups.All patients completed at least 2-year follow-up. Both groups gained significant JOA improvement postoperatively (P < .05). Preoperative and postoperative C2-C7 Cobb angle and ROM comparisons were significantly different (P < .05) in both groups. There were no significant difference for other clinical and radiography parameters between the groups (P > .05). At 2 weeks and 6 months after surgery, there was significant difference in axial symptoms between the 2 groups (P < .05). At final follow-up, the difference between the 2 groups was not statistically significant (P > .05).In different angles of the lamina open-door, incidence of axial symptoms has statistically difference between the 2 groups. When the lamina open-door angles are <40°, there are not only ensure adequate spinal cord decompression but reduces the incidence of early and midterm postoperative axial pain.

A Novel Drill Navigation Template Combines Preoperative Simulation in Expansive Open-Door Laminoplasty

To evaluate the effects of preoperative simulation based on patient-specific vertebral models, and computer-assisted designed drill navigation templates in expansive open-door laminoplasty (EOLP). We retrospectively analyzed 18 consecutive patients who underwent EOLP, 11 patients (45 vertebrae) were treated with traditional EOLP (traditional group) and 7 patients (28 vertebrae) were treated with EOLP aided by the drill navigation template and preoperative simulation (template group). We assessed the operation time, intraoperative blood loss, hospitalization expenses, visual analog scale (VAS), Japanese orthopedic association (JOA), neck disability index (NDI), Pavlov's ratio, laminoplasty opening size (LOS), hinge fracture rate and trough positions. The operation time of template group (98.6 ± 13.0 minutes) was significantly shorter (P < 0.05) than that of traditional group (125.4 ± 13.2 minutes). Both groups achieved similar hospitalization expenses and significant improvement in VAS, JOA score, NDI, and Pavlov ratio. The postoperative hinge fracture rate of template group (0%; 0/28) was significantly lower (P < 0.05) than that of traditional group (11.1%, 5/45). In template group, all the troughs (56/56 [100%]; 28/28 on the hinge side and 28/28 on the open side), while in traditional group, only 72.2% (65/90; 31/45 on the hinge side and 34/45 on the hinge side) of the troughs were at the proper hinge position. Drill navigation template and preoperative simulations in EOLP are technically feasible. With the help of templates and preoperative simulation, shorten operation time, accurate trough positioning, decrease incidence of hinge fracture and could be acquired. This technique should be further studied and affirmed in clinical applications.

Small sagittal vertical axis accompanied with lumbar hyperlordosis as a risk factor for developing postoperative cervical kyphosis after expansive open-door laminoplasty.

OBJECTIVE Preoperative positive cervical sagittal imbalance and global sagittal imbalance are risk factors for postoperative cervical kyphosis after expansive open-door cervical laminoplasty (ELAP). The purpose of this study was to investigate the relationship between the incidence of postoperative cervical kyphosis after ELAP and the preoperative global sagittal spinal alignment in patients with cervical spondylotic myelopathy (CSM) without spinal sagittal imbalance. METHODS Among 84 consecutive patients who underwent ELAP for CSM at the authors' hospital, 43 patients without preoperative cervical kyphosis (C2-7 angle ≥ 0°) and spinal sagittal imbalance (C2-7 sagittal vertical axis [SVA] ≤ 80 mm and C-7 SVA ≤ 95 mm) were included in the study. The global spinal sagittal parameters were measured on lateral whole-spine standing radiographs preoperatively and at 1 year postoperatively. The difference in preoperative global sagittal spinal alignment between the postoperative cervical lordosis group and the cervical kyphosis group was analyzed. RESULTS The incidence of postoperative cervical kyphosis after ELAP was 25.6% (11 of 43 cases). Thirty-two patients (16 men and 16 women; mean age 67.7 ± 12.0 years) had lordosis, and 11 (7 men and 4 women; mean age 67.2 ± 9.6 years) had kyphosis. The preoperative C-7 SVA and pelvic incidence minus lumbar lordosis (PI-LL) in the kyphosis group were significantly smaller than those in the lordosis group (p < 0.05). The smaller C-7 SVA accompanied by a small PI-LL, the "truncal negative offset," led to postoperative cervical kyphosis due to posterior structural weakening by ELAP. CONCLUSIONS In patients with CSM without preoperative cervical and global spinal sagittal imbalance, a small SVA accompanied by lumbar hyperlordosis is the characteristic alignment leading to postoperative cervical kyphosis after ELAP.

Correlation analysis of preoperative T 1 slope in MRI and physiological curvature loss after expansive open-door laminoplasty

To investigate whether preoperative T 1 slope (T 1S) in MRI can predict the changes of cervical curvature after expansive open-door laminoplasty (EOLP) in patients with cervical spondylotic myelopathy, so as to make up for the shortcomings of difficult measurement in X-ray film. The clinical data of 36 patients with cervical spondylotic myelopathy who underwent EOLP were retrospectively analysed. There were 21 males and 15 females with an average age of 55.8 years (range, 37-73 years) and an average follow-up time of 14.3 months (range, 12-24 months). The preoperative X-ray films at dynamic position, CT, and MRI of cervical spine before operation, and the anteroposterior and lateral X-ray films at last follow-up were taken out to measure the following sagittal parameters. The parameters included C 2-C 7 Cobb angle and C 2-C 7 sagittal vertical axis (C 2-C 7 SVA) in all patients before operation and at last follow-up; preoperative T 1S were measured in MRI, and the patients were divided into larger T 1S group (T 1S>19°, group A) and small T 1S group (T 1S≤19°, group B) according to the median of T 1S, and the preoperative T 1S, C 2-C 7 Cobb angle, C 2-C 7 SVA, and the C 2-C 7 Cobb angle and C 2-C 7 SVA at last follow-up, difference in axial distance (the difference of C 2-C 7 SVA before and after operation), postoperative curvature loss (the difference of C 2-C 7 Cobb angle before and after operation), the number of patients whose curvature loss was more than 5° after operation, and the number of patients whose kyphosis changed (C 2-C 7 Cobb angle was less than 0° after operation). The C 2-C 7 Cobb angle at last follow-up was significantly decreased when compared with preoperative value ( t=8.000, P=0.000), but there was no significant difference in C 2-C 7 SVA between pre- and post-operation ( t=-1.842, P=0.074). The preoperative T 1S was (19.69±3.39)°; there were 17 cases in group A and 19 cases in group B with no significant difference in gender and age between 2 groups ( P>0.05). The preoperative C 2-C 7 Cobb angle in group B was significantly lower than that in group A ( t=-2.150, P=0.039), while there was no significant difference in preoperative C 2-C 7 SVA between 2 groups ( t=0.206, P=0.838). At last follow-up, except for the curvature loss after operation in group B was significantly lower than that in group A ( t=-2.723, P=0.010), there was no significant difference in the other indicators between 2 groups ( P>0.05). Preoperative larger T 1S (T 1S>19°) in MRI had a larger preoperative lordosis angle, but more postoperative physiological curvature was lost; preoperative T 1S in MRI can not predict postoperative curvature loss, but preoperative larger T 1S may be more prone to kyphosis.

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

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

Factors associated with postoperative C5 palsy after expansive open-door laminoplasty: retrospective cohort study using multivariable analysis.

The aim of the present study was to investigate the factors associated with C5 palsy by focusing on radiological parameters using multivariable analysis. The authors retrospectively assessed 190 patients with cervical spondylotic myelopathy treated by open-door laminoplasty. Four radiographic parameters-the number of expanded lamina, C3-C7 angle, lamina open angle and space anterior to the spinal cord-were evaluated to clarify the factors associated with C5 palsy. Of the 190 patients, 11 developed C5 palsy, giving an overall incidence of 5.8%. Although the number of expanded lamina, lamina open angle and space anterior to the spinal cord were significantly larger in C5 palsy group than those in non-palsy group, a multiple logistic regression analysis revealed that only the space anterior to the spinal cord (odds ratio 2.60) was a significant independent factor associated with C5 palsy. A multiple linear regression analysis indicated that the lamina open angle was associated with the space anterior to the spinal cord and the analysis identified the following equation: space anterior to the spinal cord (mm)=1.54+0.09×lamina open angle (degree). A cut-off value of 53.5° for the lamina open angle predicted the development of C5 palsy with a sensitivity of 72.7% and a specificity of 83.2%. The larger postoperative space anterior to the spinal cord, which was associated with the lamina open angle, was positively correlated with the higher incidence of C5 palsy.

C4/5 foraminal stenosis predicts C5 palsy after expansive open-door laminoplasty.

Laminoplasty is frequently performed in cervical myelopathy patients, but can lead to unexpected postoperative C5 palsy. Although several studies have examined the pathogenesis and prevention of postoperative C5 palsy, many controversies remain and some radiological findings identified as risk factors were not correlated with our outcomes. This study sought reliable radiological findings that predict C5 palsy after laminoplasty and examined why the predictors of C5 palsy did not apply in our series. This study reviewed 116 patients who underwent open-door laminoplasty for cervical spondylotic myelopathy between January 2014 and April 2016, retrospectively. C5 palsy was defined as weakness of the deltoid muscle. We evaluated the incidence of C5 palsy, the preoperative C2-7 Cobb's angle, and Pavlov ratio at the C4/C5 level using simple cervical lateral radiographs. We also evaluated the existence of an ossified posterior longitudinal ligament, the transverse diameter of the C4/5 foramen, and increases in the anteroposterior diameter of the spinal canal at the C4/5 levels after surgery. Furthermore, a high signal intensity on T2-weighted images of the cervical spinal cord preoperatively was noted. Of the 116 patients, 16 cases were excluded and 100 cases were analyzed; postoperative C5 palsy occurred in 8 patients (8%). There were no significant differences between the two groups except the average diameter of the C4/5 foramen. A diameter of the C4/5 foramen of less than 2mm was significantly related to C5 palsy in the binary logistic regression test. A smaller diameter of the C4/5 foramen was the only factor significantly correlated with C5 palsy after laminoplasty. The results suggest that C4/5 foraminal stenosis is one of the best predictors of C5 palsy, which might be related to ischemic/reperfusion injury of the C5 root nerve after laminoplasty.

Comparison of the effects of different fixation methods on open-door side in posterior expansive open-door laminoplas-ty

Objective To investigate the clinical outcome and complications of different types of expansive open door laminoplasty in cervical spondylotic myelopathy. Methods From December 2008 to June 2012, 221 patients with cervical spondylotic myelopathy treated with expansive open-door laminoplasty were divided into micro-titanium plate fixed group (96 cases), wire hanging fixed group(66 cases), anchor suspension fixed group (59 cases). The clinical outcome was evaluated in-cluding JOA score, operation time, bleeding volume, spinal cord pressure (a/M), cervical range of motion (ROM), open door an-gle, posterior shift distance of spinal cord and postoperative complications. Results All patients were followed up for more than 2 years. There were no significant differences in general condition, operation time, intraoperative blood loss, preoperative and post-operative 2 years JOA score, JOA score improvement rate, spinal cord shift distance, spinal cord compression among three groups; In the incidence of C5 nerve root paralysis, there was no significant difference between the silk suspension fixation group (12.1%) and the anchored suspension group (11.9%). The incidence of C5 nerve root paralysis for microplate fixation group (2.1%) was sig-nificantly lower than that of the silk suspension fixation group and anchored suspension fixation group, and the difference was sta-tistically significant. There was no significant difference in the fusion rate between the 3-month and 6-month portal arteries in the group of silk suspension fixation group(65%, 82%) and anchor fixation group(61%, 82%). The fusion rate of the microtiter plate fix-ation group(90%, 98%) was significantly higher than that of the silk suspension group and the anchorage group at 3 months and 6 months after operation. There were no significant differences in the incidence of recurrence, the total amount of cervical spine loss and the incidence of axial symptoms after 6 months of operation in the suspension group and the anchor suspension group. The in-cidence of occlusion, the total amount of cervical spine loss and the incidence of axial symptoms were significantly lower in the mi-cro titanium plate fixation group than those in the silk suspension group and the anchorage fixation group, the difference was statis-tically significant. Conclusion Using micro-titanium plate to fix the side of open door could achieve full spinal cord decompres-sion and access to satisfactory neurological improvement rate. At the same time, compared with the traditional silk or anchor sus-pension, the use of micro-titanium plate is more conducive to the door axis bone healing, prevent the occurrence of reclosing, sig-nificantly reduce the loss of postoperative cervical range of motion, and reduce the incidence of axial symptoms with the satisfac-tion of the clinical outcome. Key words: Cervical vertebrae; Spinal cord compression; Decompression, surgical; Postoperative complications; Radicu-lopathy

Cervical expensive open-door laminoplasty combined with vitamin B12 treatment for patients of cervical spondylotic myelopathy with subacute combined degeneration of the spinal cord

Objective To investigate the clinical outcome of cervical expensive open-door laminoplasty combined with vitamin B12 treatment for patients of cervical spondylotic myelopathy with subacute combined degeneration of the spinal cord. Methods Data of 10 patients with cervical spondylotic myelopathy with subacute combined degeneration of the spinal cord in February 2013 to August 2013 were retrospectively analyzed. There were 7 males and 3 females with an average age of 46 years (range, 32-73 years). Eight patients’ history was in six months, and others’ was beyond six months. All patients had undergone cervical expansive open-door laminoplasty with mini-plate fixation combined with intramuscular injection or pre os vitamin B12. Patient imaging data were used to assess the stability of the cervical spine, and spinal cord compression in the fixed position before and after their surgery. Japanese Orthopaedic Association (JOA) score was used to evaluate function, and the rate of neurological improvement was calculated. The American Spinal Injury Association was used to evaluate the neurological function inpatients be-fore and after surgery. The preoperative and postoperative numerical changes of SEP and vitamin B12 were compared using corre-lation analysis. Each dimension of preoperative and postoperative scores change was compared by Life quality evaluation F-36 scale. Results All patients were followed up for an average period of 15 months (range, 6-26 months). There were no complica-tions related to the internal fixation, such as fixation loosened or broken. Cerebrospinal fluid surrounding the spinal cord within the C3-7 range of the signal on MRI T2WI of the continuous had been recovered. JOA score increased from preoperative 9.6±2.04 to postoperative 14.7±2.04, and postoperative neurological improvement rate was 20%-80%. The excellent and good rate was 90% (9/10) including 4 excellent and 5 good. Vitamin B12 level before operation: 78.30±42.82 pg/ml, postoperative: 176.50±85.77 pg/ml. Electromyography and SEP had been all recovered. There was correlation between preoperative and postoperative vitamin B12 lev-els with spinal cord function score. According to ASIA score, there were 4 cases in C level, 6 in D level preoperatively, while 2 in C level, 5 in D level, 3 in E level postoperatively. Conclusion Cervical spondylotic myelopathy with subacute combined degen- eration of the spinal cord could be treated by surgery. Vitamin B12 by per os or intramuscular injection with removal of the cervi-cal spinal cord compression which creates a space for recovery of spinal cord could improve the surgical curative effect. Key words: Cervical vertebrae; Vitamin B12 deficiency; Subacute combined degeneration

Dynamic consideration of expansive open-door laminoplasty by finite element analysis : about modeling method of cervical vertebra

Dynamic consideration of expansive open-door laminoplasty by finite element analysis : about modeling method of cervical vertebra

Expansive open-door laminoplasty versus laminectomy and instrumented fusion for cases with cervical ossification of the posterior longitudinal ligament and straight lordosis.

To identify whether expansive open-door laminoplasty (Lam) is more appropriate than laminectomy and instrumented fusion (LIF) for cases with ossification of the posterior longitudinal ligament (OPLL) and straight cervical lordosis. A total of 67 cases were included and divided into Group Lam (n=32) and Group LIF (n=35), and the mean follow-up periods were 38 and 42months, respectively. The cervical lordosis was elevated by C2-7 Cobb angle and cervical sagittal balance by C2-C7 sagittal vertical axis (SVA). Japanese Orthopedic Association (JOA), neurological recovery rate (RR) being calculated by the JOA, visual analog scale (VAS) and neck disability index (NDI) were used to assess clinical outcomes. Differences in general data between two groups were not significant. Total blood loss and operation duration in Group Lam were both significantly less than that in the Group LIF. By the final follow-up, the cervical lordosis significantly decreased in Group Lam and increased in Group LIF, the SVA significantly increased in Group Lam and kept unchanged in Group LIF, and the JOA, VAS, NDI significantly improved in both groups. Although there was no significant difference in RR between the two groups, cases in Group Lam had significantly larger incidence of postoperative kyphosis and kyphotic change rate, and less VAS, NDI and incidence of axial pain than cases in Group LIF. When compared with the LIF, the Lam is recommended for cases with OPLL and straight cervical lordosis when taking comparable neurological recovery, less axial pain and better neck function improvement into consideration.

Posterior cervical open-door expansive laminoplasty with mini-titanium plate: correlation between cervical sagittal alignment and repair effect

Posterior cervical open-door expansive laminoplasty with mini-titanium plate: correlation between cervical sagittal alignment and repair effect

Safety and efficacy of cervical laminoplasty using a piezosurgery device compared with a high-speed drill

Background:Piezosurgery is a relatively new osteotomy technique using microvibrations of scalpels at ultrasonic frequencies to perform safe and effective osteotomies without damage to adjacent soft tissue, which is widely used in spinal, oral, and maxillofacial surgery. We hypothesized that such a device could also be useful in cervical laminoplasty. The purpose of this study was to compare the safety and efficacy of a piezosurgery device with those of a highspeed drill in cervical laminoplasty.Methods:A prospectively randomized clinical study was designed. Forty-two consecutive patients were enrolled in the study. All patients underwent modified expansive open-door laminoplasty and were randomly divided into 2 groups according to the instrument for transection of the lamina, using high-speed drill (drill group) or piezosurgery device (piezosurgery group). The operation time, intraoperative blood loss, and postoperative drainage were recorded. Japanese Orthopedic Association (JOA) score and visual analogue scale (VAS) as clinical assessments were quantified.Results:No significant difference was observed in the operation time between the 2 groups. In the piezosurgery group, there were less loss of the intraoperative blood and postoperative drainage compared with the drill group. However, clinical results (VAS and JOA scores) showed no significant difference between both groups during the all follow-up periods.Conclusion:The piezosurgery is a useful instrument and at least as safe and efficacious as the conventional high-speed drill in cervical laminoplasty.

Dorsal open reduction with pedicle screw rod internal fixation for lower cervical spine dislocation: A retrospective analysis of 12 cases

BackgroundLower cervical spine dislocation remains a surgical challenge. MethodsTwelve patients with lower cervical dislocation due to articular process injury underwent dorsal open reduction and manual pedicle screw rod fixation. Patients with cervical spinal cord injury received simultaneous open door expansive laminoplasty. Neurological function was evaluated using ASIA Impairment Scale 12. ResultsMedian time from injury to operation was 10 days (range, 5 to 52 days). Anatomic reduction was achieved in all patients. In nine patients with cervical spinal cord injury, 55.5% (5/9) showed improvement in ASIA grade following surgery. Unilateral numbness of the superior radicular area in one patient resolved 2 weeks post-surgery and two cases (11.1%, 2/9) had postoperative leakage of the cerebrospinal fluid, which resolved in 11 days and 13 days, respectively. ConclusionDorsal open reduction and manual pedicle screw rod fixation is safe and effective for lower cervical spine dislocation due to articular process injury.

Use of rapid prototyping drill template for the expansive open door laminoplasty: A cadaveric study

ObjectiveTrough preparation is a technically demanding yet critical procedure for successful expansive open door laminoplasty (EOLP), requiring both proper position and appropriate bone removal. We aimed to use the specific rapid prototyping drill template to achieve such requirement. MethodsThe 3D model of the cadaveric cervical spine was reconstructed using the Mimics 17.0 and Geomagic Studio 12.0 software. The drilling template was designed in the 3-Matic software. The trough position was simulated at the medial margin of the facet joint. Two holders were designed on both sides. On the open side, the holder would just allow the drill penetrate the ventral cortex of the lamina. On the hinge side, the holder was designed to keep the ventral cortex of the lamina intact. One orthopedic resident performed the surgery using the rapid prototyping drill template on four cadavers (template group). A control group of four cadavers were operated upon without the use of the template. ResultsThe deviation of the final trough position from the simulated trough position was 0.18mm±0.51mm in the template group. All the troughs in the template group and 40% of the troughs in the control group were at the medial side of the facet joint. The complete hinge fracture rate was 5% in the template group, significantly lower than that (55%) in the control group (P=0.01). ConclusionThe rapid prototyping drill template could help the surgeon accomplish proper trough position and appropriate bone removal in EOLP on the cadaveric cervical spine.

Long-term outcomes and prognostic analysis of modified open-door laminoplasty with lateral mass screw fusion in treatment of cervical spondylotic myelopathy.

ObjectivesThe purpose of the present study was to explore and analyze the long-term outcomes and factors that affect the prognosis of expansive open-door laminoplasty with lateral mass screw fusion in treatment of cervical spondylotic myelopathy (CSM).MethodsWe retrospectively reviewed 49 patients with multilevel CSM who had undergone expansive open-door laminoplasty with lateral mass screws fixation and fusion in our hospital between February 2008 and February 2012. The average follow-up period was 4.6 years. The clinical data of patients, including age, sex, operation records, pre- and postoperation Japanese Orthopedic Association (JOA) scores, cervical spine canal stenosis, and cervical curvature, were collected. Increased signal intensity (ISI) on T2-weighted magnetic resonance imaging and ossification of the posterior longitudinal ligament were also observed. Paired t-test was used to analyze the treatment effectiveness and recovery of neuronal function. The prognostic factors were analyzed with multivariable linear regression model.ResultsForty-nine patients with CSM with a mean age of 59.44 years were enrolled in this study. The average of preoperative JOA score was 9.14±2.25, and postoperative JOA score was 15.31±1.73. There was significant difference between the pre- and postoperative JOA scores. The clinical improvement rate was 80.27%. On follow-up, five patients had complaints of neck and shoulder pain, but no evidence of C5 nerve palsy was found. Developmental cervical spine canal stenosis was present in all patients before surgery. Before surgery, ISI was observed in eight patients, while ossification of the posterior longitudinal ligament was found in 12 patients. The average of preoperative cervical curvature was 21.27°±8.37° and postoperative cervical curvature was 20.09°±1.29°, and there was no significant difference between the pre- and postoperative cervical curvatures. Multivariable linear regression analysis results showed that the postoperation JOA scores were significantly affected by age, preoperative JOA scores, and preoperative ISI. Except one case of epidural hematoma, there were no complications associated with the surgery.ConclusionTreatment of CSM with posterior open-door laminoplasty with lateral mass screw fusion is effective with few complications. In addition, the normal cervical lordosis was well maintained. Age, preoperative JOA scores, and preoperative ISI were the independent factors that significantly affect disease prognosis and surgical outcomes.

Anatomic and functional reconstruction of the spinal posterior column after resection of intraspinal neoplasms

Objective To investigate the operative outcomes of anatomic and functional reconstruction of the spinal posterior column after resection of intraspinal neoplasms. Methods From January 2010 through October 2014, we treated 32 patients with intraspinal neoplasm in the spine. They were 18 men and 14 women, 13 to 62 years of age (average, 38 years). The neoplasm was detected in the cervical spine in 10 cases, in the thoracic spine in 14 and in the lumbar spine in 8. All cases received expansive open door laminoplasty via the posterior approach for resection of the intraspinal neoplasm, followed by replantation and titanium plate fix-ation for anatomic and functional reconstruction of the spinal posterior column. The neural functional recovery, spinal motion and sagittal diameter of the spinal canal before and after operation, spinal stability and graft fusion were observed. Results The patients were followed up for 3 to 23 months (average, 13 months). All the intraspinal neoplasms were completely resected. The Frankel grading of neural functional recovery was improved differently in all the cases. By the final follow-ups, the spinal motion was normal in all the cases, without any significant limitation. Graft fusion and rigid internal fixation were achieved in all the cases. Short-term follow-ups revealed no signs of spondylolisthesis or spinal instability. At the final follow-ups, the 3-D CT reconstruction showed no significant shortening in the sagittal diameter of the same spinal canal before and after operation (P >0.05). Conclusions For intraspinal neoplasm in the spine, the whole vertebral lamina is opened or re-moved via the posterior approach to resect the neoplasm, followed by reduction of the vertebral lamina and mini titanium plate fixation to reconstruct the anatomy and function of the original spine. This is an ideal way to treat intraspinal neoplasms in the spine. Key words: Spine; Reconstructive surgical procedure; Treatment outcome; Posterior approach

Laminar closure after expansive open-door laminoplasty: fixation methods and cervical alignments impact on the laminar closure and surgical outcomes

Background ContextAlthough several laminar fixation methods in expansive open-door laminoplasty (EODL) have been reported, the differences in outcomes between the methods have not been well understood. PurposeThe aim of this study were to investigate the impact of laminar fixation methods and cervical spine alignment after EODL on clinical and radiological outcomes, and to investigate the impact of laminar closure on clinical outcomes. Study DesignThis study is a retrospective review of clinical and radiological data. Patient SampleThe inclusion criteria were having undergone EODL with suture anchor (n=74, Anchor group) or hydroxyapatite spacers (n=65, Spacer group) for cervical spondylotic myelopathy (CSM). Different surgical procedures were used during two time periods: anchor technique from 2001 to 2006, and spacer technique from 2007 to 2012. Outcome MeasuresJapanese Orthopaedic Association (JOA) scores for cervical myelopathy were recorded. Cross-sectional areas (CSA) were measured preoperatively, and at 1 week, 6 months, and 2 years postoperatively at each level (C3–C6) using reconstructed axial computed tomography (CT) images. The CSA decrease of more than 20% was defined as laminar closure. MethodsThe JOA scores and the CSA values were compared between the two groups (Anchor group vs. Spacer group) and subgroups (preoperative kyphosis vs. lordosis alignment, closure vs. non-closure groups). ResultsIn both groups, the mean CSA decreased at 6 months postoperatively compared with that at 1 week postoperatively. The CSA further decreased at 2 years postoperatively in the Anchor group but remained unchanged after 6 months in the Spacer group. The CSA remained unchanged in patients with preoperative lordosis in both groups. However, patients with kyphosis in the Anchor group showed a continuously decreasing CSA throughout the follow-up period, whereas CSA was stable in patients with kyphosis in the Spacer group (p<.01). Although the preoperative JOA scores did not differ between the closure and non-closure group (p=.924), the JOA score was significantly worse in the closure group at 1 and 2 years postoperatively (p=.023 and p=.011 respectively). ConclusionsThe patients with CSM with kyphosis in the Spacer group experienced significantly less laminar closure after EODL compared with patients in the Anchor group. Laminar closure greater than 20% was associated with poor outcome. Therefore, spacer fixation is preferable to anchor screw fixation during EODL in patients with kyphosis.

Use of Miniplates and Local Bone Grafts to Prevent Spring Back in Laminoplasty for Cervical Spondylotic Myelopathy: 用金屬小綱板和骨移植來防止椎板回彈的技術在椎板成形術中的應用

Background/PurposeCervical spondylotic myelopathy/ossification of posterior longitudinal ligament can be treated by anterior or posterior decompression. For multiple levels, it is common to perform posterior decompression by laminoplasty. Hirabayashi described his open-door expansive laminoplasty in 1977, which soon became popular. Spring back of the lamina has always been a problem. Many methods including suturing to soft tissue, suture anchors, bone grafts, hydroxyapatite blocks, and ceramic spacers were used to prevent this problem, but with considerable failure. Recently, miniplates were used to prevent spring back. MethodsTwenty-nine consecutive patients who had underwent Hirabayashi open-door expansive laminoplasty in a single centre were recruited in this retrospective study. Miniplates were used to keep the laminae open. In addition, the spinous processes of lower cervical vertebrae were excised and used as local bone grafts to fill the gap between the cut laminae. Computerized tomography scans were performed postoperatively for all patients to assess bone union and spring back. ResultsA total of 126 levels of laminoplasty and 51 local bone grafts were studied. The minimal follow-up period was 12 months. Signs of bone union were demonstrated in 123 hinges (97.6%) and 51 bone grafts (100%). No spring back was detected. The clinical outcome in terms of Hirabayashi recovery rate was 47.2%. ConclusionMiniplates and local bone grafts are promising and effective tools for preventing spring back in cervical laminoplasty.

Prevalence of axial symptoms after posterior cervical decompression: a meta-analysis.

To investigate the prevalence of axial symptoms (AS) in patients following posterior cervical decompression. We searched the PubMed, Embase, and Cochrane databases for relevant studies that reported the incidence of AS after posterior cervical decompression, and manually screened reference lists for additional studies. Relevant prevalence estimates were calculated. Subgroup analysis, sensitivity analysis and publication bias assessment were also performed. Our meta-analysis included 44 studies, with 893 AS cases in 2984 patients. The pooled AS prevalence was 28% (95% CI 24-32). The prevalence of AS was higher after expansive open-door laminoplasty (39%) than after modified open-door laminoplasty (MOLP, 23%) and laminectomy instrumented fusion (29%). AS prevalence was also higher in those that wore a neck collar for 2-3months (34%) compared with 2weeks (21%). The lowest AS prevalence (9%) was found in patients who underwent MOLP with C3 laminectomy and C7 spinous processes conserved. There was an intermediate AS prevalence after MOLP with C7 spinous processes conserved (16%), MOLP with preservation of the unilateral posterior muscular-ligament complex (19%), MOLP with C3 laminectomy (22%), and MOLP with plate fixation (23%). Prevalence of AS might be higher in patients <60years and increased in populations with a higher proportion of females. Posterior cervical surgery carries a high risk of postoperative AS. Postoperative AS may be reduced through preserving posterior muscles and structures, stabilizing cervical vertebrae, and reducing external cervical immobilization time.