Expansive Open-door Laminoplasty Research Articles

Effect of posterior cervical expansive open-door laminoplasty on cervical sagittal balance.

Posterior cervical expansive open-door laminoplasty (LAMP) is a mature surgical procedure for the treatment of cervical spondylotic myelopathy (CSM), but there are few studies on the changes in cervical sagittal balance. This study aimed to analyze the imaging and clinical data of patients who underwent LAMP and to explore the effect of this procedure on the cervical sagittal balance. This was a retrospective study of the patients who underwent LAMP between 01/2014 and 12/2017. The C0-C2 Cobb angle, sagittal vertical angle (SVA), C2-C7 Cobb angle, and T1-slope were measured. The Japanese Orthopaedic Association (JOA) score, neck disability index (NDI), and visual analog scale (VAS) were used. There were 69 males and 39 females. The mean age was 61.3 ± 5.3years. The C0-C2 Cobb angle increased from 11.3 ± 5.5° to 26.8 ± 4.8° (P = 0.186). The C2-C7 Cobb angle decreased from 13.9 ± 8.6° to 10.65 ± 10.7° P = 0.016). SVA increased from 21.0 ± 5.8mm to 25.4 ± 11.5mm (P = 0.001). The preoperative average JOA score was 11.1 ± 2.2 points, and the postoperative score was 14.0 ± 2.1 points, with an average improvement rate of JOA of 46.5 ± 3.8%. The NDI score decreased from preoperative 15.6 ± 5.4 points to 11.3 ± 7.9 points, and the VAS score was decreased from 4.6 ± 1.8 points to 3.3 ± 1.6 points (all P < 0.05). LAMP improved the neurological function and quality of life of patients with CSM. The cervical vertebrae show a tendency of tilting forward, suggesting that overextension of the upper cervical vertebra might be used to maintain the center of gravity of the skull and horizontal vision.

Effect of Titanium Miniplate Fixation on Hinge Fracture and Hinge Fracture Displacement Following Cervical Open-Door Laminoplasty

Cervical spondylotic myelopathy is a neuromotor disorder responsible for functional limitations and decreased daily activities. Expansive open-door laminoplasty is the widely accepted procedure for the treatment of multilevel cervical spondylotic myelopathy. Among the various fixation procedures to secure the open lamina, miniplate fixation provides better clinical and radiological outcomes. However, the immediate effects on hinge fracture and hinge fracture displacement following miniplate fixation have not been proven until now. The purpose of our study was to elucidate the impact of cervical open-door angle on the status of spinal cord expansion and hinge fracture, hinge fracture displacement, and the role of implants used during surgery. For this retrospective study, 122 patients who had undergone surgery from September 2016 to November 2017 with preoperative and postoperative radiographs were enrolled. Clinical and radiological outcomes were assessed before and after surgery. There were no significant differences in demographics, surgery time, blood loss, medical comorbidities, or perioperative and postoperative complications between 2 groups. The recovery rate and Nurick score before and at the follow-up show no statistical significance between the 2 groups, P value > .05 (P = .672) and P > .05 (P = .553), respectively. The statistical analysis shows that the mean hinge fracture in the miniplate group with a cervical open angle >30° was 2.42 ± 1.68 and with a <30° open angle, 0.05 ± 0.23; whereas, in the anchor group the mean hinge fracture in >30° cervical open angle was 2.227 ± 2.50 and in <30° was 0.409 ± 0.503. The results revealed statistical significance between 2 implant groups, P = .024 in the aspect of hinge fracture displacement and implant used. Laminoplasty by titanium miniplate fixation holds the laminae securely, prevents hinge fracture displacement, and promotes spinal cord expansion better than suture anchor fixation.

Withdrawal notice to The anatomical mechanism of C5 palsy after expansive open-door laminoplasty

BACKGROUNDPostoperative C5 palsy is not an uncommon complication in patients who undergo expansive open-door laminoplasty. However, the etiology is unclear and likely multifactorial. Nerve root lesions and spinal cord lesions have been previously proposed theories. PURPOSETo investigate the anatomical mechanism of postoperative C5 palsy after cervical expansive open-door laminoplasty. STUDY DESIGNA dissection-based study of eight embalmed human cadavers. METHODSThe anatomy was studied in eight whole cervical cadavers (three females, five males), prepared with formaldehyde, whose ages at the time of death ranged from 54 to 78 years. Dissection was performed on the intervertebral foramen and spinal canal. In the C3–C7 of the cervical vertebra, the extraforaminal ligaments and the meningovertebral ligaments were observed. The length, width, and thickness of the ligaments were measured with a Vernier caliper. After an expansive open-door laminoplasty was performed, the shape of the dural sac was changed, and displacement of the nerve root was observed. In addition, the lengths of the anterior rootlets were measured. This study has been supported by grants from Science and Technology Planning Project of Guangdong Province (CN) (Grant No. 2017B020210010) without potential conflict of interest-associated biases in the text of the paper. RESULTSOne hundred seventy-seven extraforaminal ligaments were found to connect the spinal nerve to the surrounding structures. After an expansive open-door laminoplasty was performed, posterior distension of the dural sac and movement of the spinal cord and nerve root were found. The spinal cord was closely attached to the ligamentum flavum by meningovertebral ligaments. In addition, the length of the C5 intradural rootlets (5.81–10.59 mm) was the shortest among the vulnerable segments. CONCLUSIONTraction on and posterior movement of the extradural roots may be the main pathologic mechanism of postoperative C5 palsy when expansive open-door laminoplasty is performed. The meningovertebral ligaments and extraforaminal ligaments might play an important role in the occurrence of postoperative C5 palsy. CLINICAL SIGNIFICANCEThis study provides clinicians with a more detailed understanding of the anatomic structure and potential mechanism of C5 palsy. Consideration of the meningovertebral ligaments and the intervertebral foramen may provide new directions for reducing the incidence of this complication.

Factors associated with postoperative axial symptom after expansive open-door laminoplasty: retrospective study using multivariable analysis.

The aim of the present study was to investigate the factors associated with axial symptom using multivariable analysis. The authors retrospectively assessed 249 patients treated by open-door laminoplasty. The patients were classified into two groups: axial symptom and no axial symptom group. The possible factors included demographic variables (age, sex, BMI, smoking, heart disease, diabetes, preoperative neck pain, preoperative JOA scores, preoperative NDI, course of disease and pathogenesis) and surgical and radiological variables [operation time, intraoperative blood loss, collar wear time, preoperative cervical curvature, postoperative cervical curvature, T1 slope, preoperative and postoperative C2 sagittal vertical axis (C2 SVA)]. The prevalence of axial symptom was 34.9% (89/249). The collar wear time, preoperative and postoperative C2 SVA were risk factors for axial symptom. A cutoff value of 22.6mm for preoperative C2 SVA and 3.5weeks for collar wear time predicted the development of axial symptom. The longer collar wear time, larger preoperative and postoperative C2 SVA were positively correlated with the higher incidence of axial symptom.

Correlation between C7 slope and cervical lordosis in patients after expansive open-door laminoplasty

Purpose of the article: To investigate the correlation between C7 slope and cervical lordosis in patients after expansive open-door laminoplasty (EOLP).Material and methods: We retrospectively analyzed 57 patients who underwent EOLP between June 2013 and January 2017 in the Department of Spinal Surgery of our hospital. The operation time, intraoperative blood loss and follow-up time were recorded. The C7 slope, C2-7 sagittal vertical axis, and C2-7 Cobb angle were measured anteroposterior radiograph of the cervical spine preoperatively and postoperatively. All patients were divided into two groups according to the preoperative C7 slope (C7 slope ≤20° group and C7 slope >20° group).Results: The amount of intraoperative bleeding was 220.2 ± 180.9ml, and the operation time was 143.4 ± 51.2min. The average follow-up time was 24.9 ± 10.3months (range12–48 months). The C2-7 Cobb angle was 13.49 ± 10.46°at the final follow-up, which was significantly lower than that preoperatively (p = .026). But, The C7 slope and C2-7 sagittal vertical axis showed no significant difference between preoperatively and postoperatively. Preoperative and postoperative C7 slope and C2-7 Cobb angle were positively correlated to age and significant difference was observed. In the group of C7 slope >20°, significant difference was observed in term of the change of the C2-7 Cobb angle and C2-7SVA postoperatively (p = .009 and p= .020). However, there was no statistically significant difference detected in these two parameters in the group of C7 slope ≤20°.Conclusion: This study indicated that C7 slope could be used as an indicator of the change in the curvature of the cervical spine after EOLP. The loss of cervical curvature after surgery was prone to occur when C7 slope was greater than 20°, which should be noted in clinical practice.

Influence of extending expansive open-door laminoplasty to C1 and C2 on cervical sagittal parameters

BackgroundFor patients with spinal canal stenosis in the upper cervical spine who undergo C3–7 laminoplasty alone, it remains impossible to achieve full decompression due to its limited range. This study explores the extension of expansive open-door laminoplasty (EODL) to C1 and C2 for the treatment of cervical spinal stenosis of the upper cervical spine and its effects on cervical sagittal parameters.MethodsA retrospective analysis of 33 patients presenting with symptoms of cervical spondylosis myelopathy (CSM) and ossification in the posterior longitudinal ligament (OPLL) of the upper cervical spine from February 2013 to December 2015 was performed. Furthermore, the changes in the C0–2 Cobb angle, C1–2 Cobb angle, C2–7 Cobb angle, C2–7 SVA, and T1-Slope in lateral X-rays of the cervical spine were measured before, immediately after, and 1 year after the operation. JOA and NDI scores were used to evaluate spinal cord function.ResultsThe C0–2 and C1–2 Cobb angles did not significantly increase (P = 0.190 and P = 0.081), but the C2–7 Cobb angle (P = 0.001), C2–7 SVA (P < 0.001), and T1-Slope (P < 0.001) significantly increased from preoperative to 1 year postoperative. In addition, C2–7 SVA was significantly correlated with the T1-Slope (Pearson = 0.376, P < 0.001) and C0–2 Cobb angle (Pearson = 0.287, P = 0.004), and the C2–7 SVA was negatively correlated with the C2–7 Cobb angle (Pearson = − 0.295, P < 0.001). The average preoperative and postoperative JOA scores were 8.3 ± 1.6 and 14.6 ± 1.4 points, respectively, indicating in a postoperative neurological improvement rate of approximately 91.6%. The average preoperative and final follow-up NDI scores were 12.62 ± 2.34 and 7.61 ± 1.23.ConclusionsThe sagittal parameters of patients who underwent EODL extended to C1 and C2 included loss of cervical curvature, increased cervical anteversion and compensatory posterior extension of the upper cervical spine to maintain visual balance in the field of vision. However, the changes in cervical spine parameters were far less substantial than the alarm thresholds reported in previous studies. We believe that EODL extended to C1 and C2 for the treatment of patients with spinal canal stenosis in the upper cervical spine is a feasible and safe procedure with excellent outcomes.

Radiological Imaging Analysis of Cervical Expansive Open-door Laminoplasty Causing C5 Palsy

The aim of this research is to explore the difference of imaging parameters in patients with C5 palsy after cervical expansive open-door laminoplasty. A retrospective analysis was made on the clinical data of 62 patients who were diagnosed as multiple cervical spondylotic myelopathy and operated with cervical expansive open-door laminoplasty using Centerpiece titanium miniplate fixation. According to weather C5 nerve root palsy occurred after surgery, the patients were divided into normal group (group A with 8 cases) and paralysis group (group B with 54 cases). The preoperative and postoperative cervical spine angle (C2–7) enlargement rate of spinal canal, distance of spine cord shifting and cervical curvature between two groups were measured. Compare with group A (27.38±1.99°), the average lamina open angle of group B (34.56±5.55°) was larger, which were found statistically significant difference (P<0.05). In addition, there were no significant differences between two groups in C3 or C7 lamina open angle. However, significant differences were found between two groups in C4, C5 and C6 lamina open angle. The average enlargement rate of spinal canal and distance of spine cord shifting of group B were larger than group A, which was statistically differences (P<0.05). The opening angle of the lamina, the expansion rate of the spinal canal, and the distance of the spinal cord may prevent the occurrence of cervical 5 nerve root palsy in cervical expansive open-door laminoplasty.

Comparing clinical outcomes of using 3 versus 5 titanium miniplates in laminoplasty for multilevel cervical myelopathy: A prospective cohort study

Study designProspective cohort study. ObjectiveThe aim of this study was to compare clinical outcomes, radiographic changes, and complications of cervical expansive open-door laminoplasty（EOLP）for cervical multilevel myelopathy, using either 3 or 5 titanium miniplates. Summary of background dataCervical EOLP is a common and effective operation for cervical myelopathy. Standard procedures utilise either 3 or 5 titanium miniplates; however, no definite conclusion has been given yet on the relationship between clinical outcomes and the quantity of titanium miniplates. MethodWe performed a prospective study of 92 patients who underwent EOLP with either 3 (n ​= ​34) or 5 (n ​= ​58) titanium miniplates at our institution from March 2012 to June 2016. Clinical and radiologic outcomes and complications were compared. ResultCompared with the 5 titanium miniplates group, the 3 titanium miniplates group had shorter operation times and less blood loss (P ​< ​0.05) and needed fewer costs (P ​< ​0.01) during index hospitalisation. The preoperative cervical curvature angle decreased in both groups and revealed no significant differences. There was no significant difference between the two groups in the Japanese Orthopedic Association (JOA) score, JOA recovery rate, loss of range of motion (ROM), anteroposterior diameter (APD), or spinal canal complications (P ​> ​0.05). ConclusionCervical EOLP using 3 titanium miniplates is associated with shorter operation times, less blood loss, and lower operation costs compared with using 5 titanium miniplates. The translational potential of this articleExpansive open-door laminoplasty (EOLP) is an effective procedure for treating multilevel cervical spondylotic myelopathy. The present study indicated that 3 titanium miniplates could achieve similar clinical outcomes but with shorter operation times, less blood loss and operation costs compared with 5 titanium miniplates. These findings may provide some references for clinical applications.

Safety and efficacy of three-dimensional printed patient-specific drilling templates for expansive open-door laminoplasty.

Safety and efficacy of three-dimensional printed patient-specific drilling templates for expansive open-door laminoplasty.

Diagnosis value of serum infection index for early infection of patients undergoing posterior cervical expansive open-door laminoplasty

To investigate the diagnosis value of white blood cell (WBC) count, C-reactive protein (CRP), serum procalcitonin (PCT) and erythrocyte sedimentation rate (ESR) levels for early infection after posterior cervical expansive open-door laminoplasty. Discover, prevent, and treat postoperative infections promptly. The clinical data of 120 patients with early fever after posterior cervical laminoplasty from January 2010 to April 2019 were retrospectively analyzed. According to the results of bacteriological culture of wound exudate, the patients were divided into infected group(53 cases) and non-infected group(67 cases). In infection group, there were 32 males and 21 females, aged from 48 to 63 years old, with an average of(52.28±6.36) years. In non-infected group, there were 37 males and 30 females, aged from 46 to 62 years old, with an average of(51.63±5.82) years. According to the postoperative infection types, the patients in infection group were divided into 30 cases of deep surgical site infection group and 23 cases of superficial surgical site infection group. In deep surgical site infection group, there were 19 males and 11 females, aged from 50 to 63 years old with an average of (53.16±5.62) years. In superficial surgical site infection group, there were 13 males and 10 females, aged from 48 to 61 years old with an average of (52.15±5.68) years. WBC count, CRP, PCT and ESR serum infection indexes were compared between groups and within groups before and after surgery. The serum infective index data of 120 patients were collected and the sensitivity and specificity of the serum infectious index were used to diagnose the infection. Accuracy assessment of early infection diagnosis of WBC count, CRP, PCT and ESR serum infection indexes by plotting the receiver operating characteristic(ROC) curve with 1-specificity as the abscissa and sensitivity as the ordinate. There were no significant difference in WBC count, CRP, PCT and ESR serum infection indexes between infected group and non-infected group before operation(P>0.05). Postoperative WBC count, CRP, PCT and ESR infection indexes in infection group were higher than in non-infected group(P<0.05). Among patients with postoperative infection, WBC count, CRP, PCT and ESR serum infection index levels were significantly different in the different postoperative infection types (P<0.05). In non-infected group, WBC count, CRP, PCT and ESR serum infection indexes showed an overall trend of rising first and then falling. The area under curve (AUC) of WBC count infection index was 0.637(P<0.05). The AUC of CRP infection index was 0.792 (P<0.05). The AUC of PCT infection index was 0.774 (P<0.05). The AUC of ESR infection index was 0.783(P<0.05). WBC count, CRP, PCT and ESR serum infection indexes can be used for the diagnosis of early infection after posterior cervical expansive open-door laminoplasty. In addition, the comprehensive analysis of the changes of the four infection indexes can be used for the identification of different postoperative infection types. WBC count index is less accurate for early infection diagnosis, and CRP, PCT, and ESR indexes are more accurate for early infection diagnosis. In general, CRP, PCT and ESR serum infection indexes have important clinical significance for the diagnosis of early infection after posterior cervical open-door laminoplasty, which helps clinicians to detect early postoperative infection as early as possible to facilitate subsequent treatment.

Comparison of clinical outcomes of expansive open-door laminoplasty with unilateral or bilateral fixation and fusion for treating cervical spondylotic myelopathy: a multi-center prospective study

BackgroundThe present study evaluated the clinical outcomes and safety of expansive open-door laminoplasty, when securing with C4 – C6 lateral mass screw and fusion.MethodsA total of 110 patients with cervical spondylotic myelopathy (CSM) were enrolled. There were 88 male and 22 female, with mean age at 60.55 ± 10.95 years. All of the patients underwent expansive open-door laminoplasty with unilateral or bilateral C4–6 lateral mass screws fixation and fusion. Clinical data, including age, gender, operation-related information, pre- and post-operation Japanese Orthopedic Association (JOA) scores, and cervical curvatures were collected.ResultsThe mean follow-up time of the cohort was 13.61 ± 9.53 months. Among the 110 patients, 33 of them were allocated to Unilateral group, and 77 of them were in Bilateral group. The mean JOA score of the 110 patients before surgery was 10.07 ± 2.39, and the score was improved significantly to 12.85 ± 2.45 after surgery. There were no reported cases of neurological deterioration or symptom worsening. Patients in both the Unilateral group and Bilateral groups had significant improvement of JOA scores. Among all patients, the most frequently observed complications were axial symptoms (n = 7). The average preoperative cervical curvature among all patients was 15.17 ± 5.26, and the post-surgery curvature was 14.41 ± 4.29. Similar observations were found between Unilateral and Bilateral groups.ConclusionThe modified surgical approach provided satisfactory clinical outcome in patients with CSM. The unilateral and bilateral fixation appeared to provide similar outcomes, in terms of cervical curvature maintenance and improvement of clinical symptoms. However, the examination of the exact differences between the two fixation methods await further biomechanical studies.

P120. The efficacy and safety of applying ultrasonic osteotome in cervical expansive open-door laminoplasty

BACKGROUND CONTEXT Ultrasonic osteotome is a tissue-specific device which offers potential advantages of more precise bone resection, reduced soft-tissue injury, and less demand in surgical skill, and have been used widely in spinal surgery. Yet few studies have investigated its safety and efficacy until now. PURPOSE To investigate the safety and efficacy of applying ultrasonic osteotome in patients undergoing cervical expansive open-door laminoplasty. STUDY DESIGN/SETTING Retrospectiviely we collected the patients' clinical data and the follow-up image. All the patients were diagnosed as multilevel cervical spondylosis myelopathy and underwent cervical expansive open-door laminoplasty. Then we divided these patients into two groups: ultrasonic osteotome group and traditional group, by whether the ultrasonic osteotome device was used in operation. PATIENT SAMPLE From March 2015 to March 2016, 94 consecutive patients who were administrated in the spine group of orthopedic department of Peking University Third Hospital were reviewed retrospectiviely. OUTCOME MEASURES Comparison was made between the traditional method using bone rongeur or high-speed grinding, and the piezosurgery group. Duration of operation (from skin incision to closure), blood loss during surgery, volume of drainage first day after operation, remaining of drainage tube, and occurrence of cerebrospinal fluid leak were assessed between the two groups. JOA spinal cord function scoring system (17-point method) was adopted to evaluation neurological function. JOA score before operation, 3 months after operation, 12 months after operation and JOA improvement rate was compared between two groups. JOA improvement rate = (postoperative JOA score - preoperative JOA score) / (17 - preoperative JOA score) × 100%. Three months and 12 months follow-up CT scans were used to evaluate portal shaft healing by assessing C4, C5, and C6 portal bones. METHODS From March 2015 to March 2016, 94 consecutive patients who were administrated in the spine group of orthopedic department of Peking University Third Hospital were reviewed retrospectiviely. All the patients were diagnosed as multilevel cervical spondylosis myelopathy and were underwent cervical expansive open-door laminoplasty. These patients were divided into two groups: ultrasonic osteotome group and traditional group, by whether the ultrasonic osteotome device was used in operation. The parameters we studied were as follows: the duration of operation, blood loss in operation, volume of drainage at the first postoperative day, days of remaining the drainage tube, preoperative and postoperative JOA score, complication of cerebrospinal fluid leak and hinge bone nonunion. RESULTS Comparing to the traditional group, the duration of operation of the ultrasonic osteotome group was increased, but the blood loss in operation, volume of drainage at the first postoperative day and days of remaining the drainage tube of the ultrasonic osteotome group were all reduced. There is no obvious difference between the two groups when considering the cerebrospinal fluid leak. At the 3 month follow-up, the JOA score and improvement rate of JOA score showed no obvious difference between the two groups. But the hinge bone union of the traditional group is better than the ultrasonic osteotome group. At the 12 month follow-up, all the JOA score, the improvement rate of JOA score and the hinge bone union were not obviously different between the two groups. CONCLUSIONS Applying ultrasonic osteotome in patients undergoing cervical expansive open-door laminoplasty is both safe and effective. Comparing with the rongeur, ultrasonic osteotome caused the delayed union of the hinge bone, but it reduces the blood loss in operation, volume of postoperative drainage and days of remaining the drainage tube. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Hidden blood loss and its possible risk factors in cervical open-door laminoplasty.

ObjectivesTo evaluate hidden blood loss (HBL) and its possible risk factors among patients following expansive open-door laminoplasty (EOLP) for multilevel, cervical spondylotic myelopathy.MethodsThis was a retrospective analysis of data from patients over 18 years of age who underwent posterior cervical EOLP (from C3-C6) in our department from January 2017 to July 2018. HBL was calculated by deducting the observed perioperative blood loss from the calculated total blood loss (TBL) based on the fall in haematocrit level.Results45 patients (35 men and 10 women) were identified. Mean ± SD HBL was 337.2 ± 187.8 ml, which was 46.8% of the total perioperative blood loss (705.2 ± 269.6 ml). Twenty-three patients developed postoperative anaemia. Posterior cervical soft tissue was positively correlated with both TBL and hidden blood loss (HBL) and hypertension was positively correlated with TBL.ConclusionsHBL following cervical EOLP was significant and should be recognised as a detrimental factor to patient safety during the perioperative period, especially in patients with thick posterior cervical soft tissue.

Plate Fixation of Expansive Open-Door Laminoplasty Decreases the Incidence of Postoperative C5 Palsy.

Retrospective study. To compare outcomes for plate fixation versus suture suspension in expansive open-door laminoplasty (ELAP) for cervical spondylotic myelopathy (CSM). C5 palsy and laminar closure have been reported to occur after ELAP when suture suspension is used to anchor the opened lamina. We assessed 174 patients with CSM who were treated by ELAP using either suture suspension (114 patients, mean age 63.3 y, 83 men and 31 women, mean follow-up 12.0 mo) or laminoplasty plate (60 patients, mean age 65.6 y, 45 men and 15 women, mean follow-up 12.6 mo) to maintain the position of the opened laminae. We compared clinical outcomes, radiographic findings, and complications between the 2 groups. Mean Japanese Orthopaedic Association scores had improved significantly for both groups at the final follow-up (P<0.001), with similar recovery rates: scores improved from 10.8±2.8 to 13.4±2.8 points in the suture-suspension (SS) group and from 11.3±2.7 to 13.6±2.2 points in the laminoplasty plate (LP) group. The incidence of C5 palsy was significantly higher in the SS group (7.9%) than in the LP group (1.7%; P<0.05). Computed tomography (CT) showed larger mean angles of the opened laminae in the SS group compared with the LP group (P<0.01). Magnetic resonance imaging (MRI) showed that the mean anterior spinal-cord space at the C5 level was larger in the SS group than in the LP group (P<0.01). Plate fixation in ELAP produced comparable clinical outcomes and significantly lowered the incidence of C5 palsy compared with suture suspension. CT and MRI findings indicated that laminoplasty plate fixation prevented excessive opening of the lamina and decreased dorsal spinal-cord shift, which might explain the lower incidence of C5 palsy.

The Use of Preoperative and Intraoperative Pavlov Ratio to Predict the Risk of Postoperative C5 Palsy after Expansive Open-Door Laminoplasty for Cervical Myelopathy.

Background:No standard preoperative preventive measure has been established to decrease the occurrence of C5 palsy after expansive open-door laminoplasty. The aim of this study is to establish a reliable measured parameter in predicting the risk of the postoperative C5 palsy.Materials and Methods:A total of 276 patients receiving posterior open-door laminoplasty for cervical spinal stenotic myelopathy were studied. The patients were divided into two groups according to the preoperative Pavlov ratio (Group A: Pavlov ratio <0.65 and Group B: Pavlov ratio ≥0.65). Correlations between the occurrence of postoperative C5 palsy and Pavlov ratio were analyzed, and Group A was further tested. The surgical procedures, clinical symptoms, and Pavlov ratio were described.Results:The patients with Pavlov ratio <0.65 had a higher risk of developing postoperative C5 palsy (P < 0.05, odds ratio [OR] = 2.91). No significant difference was found in gender, age, etiology, type of operation, and pre- and postoperative Japanese Orthopaedic Association scores between patients with and without postoperative C5 palsy. The cutoff (1.01) of receiver operating characteristic curve of the postoperative Pavlov ratio of the Group A was calculated. The postoperative Pavlov ratio ≥1.01 of the patients in Group A was a significant risk factor of the development of postoperative C5 palsy (P < 0.01, OR = 10.83).Conclusions:The preoperative Pavlov ratio <0.65 at the C5 level was more likely to develop the postoperative C5 palsy. When the preoperative Pavlov ratio is <0.65, the postoperative Pavlov ratio ≥1.01 at the C5 level is a reliable predictor for the development of postoperative C5 palsy. Pavlov ratio may be one of the reasons for postoperative C5 palsy.

Medium-term clinical outcomes of laminoplasty with adjunct short anterior fusion in multilevel cervical myelopathy.

Objectives:Expansive open-door laminoplasty (EOLP) is effective for multilevel cervical spondylotic myelopathy (MCSM). When MCSM is combined with one- or two-level segmental kyphosis, instability, or major anterior foci, EOLP with short-segment anterior cervical fusion (ACF) results in good short-term neurological recovery and can preserve postoperative range of motion (ROM). The objective of this study was to evaluate the medium-term clinical outcomes of this procedure and to analyze the risk factors affecting the neurological function at the last follow-up.Materials and Methods:A total of 87 patients were enrolled in this retrospective study conducted from January 2007 to May 2011. These patients exhibited MCSM with combined short segmental kyphosis, instability, or major anterior pathology, and received EOLP and short-segment anterior fusion. The follow-up period lasted at least 60 months. The radiographic outcomes were collected from plain radiographs with dynamic views checked preoperatively and at the last follow-up. Neurological status and visual analog scale scores for neck pain were evaluated. Logistic regression analysis was then applied to determine the correlation between radiographic parameters and rates of neurological recovery.Results:The mean Japanese Orthopedics Association recovery rate at the last follow-up was 77.8%. The improvement in functional scores and reduction in neck pain were statistically significant. The most influential risk factor affecting neurologic recovery was preoperative functional status.Conclusions:EOLP followed by short-segment ACF is a favorable treatment for patients with MCSM with concomitant short-segment kyphosis, instability, or major anterior pathology.

A clinical Study of C2 dome-like expansive laminoplasty and C2 expansive open-door laminoplastyinupper cervical ossifi-cation of the posterior longitudinal ligament

Objective To explore the clinical effects of C2 dome-like expansive laminoplasty and C2 expansive open-door laminoplasty in upper cervical(involve or above C2 segment) ossification of the posterior longitudinal ligament. Methods All of 39 patients (22 males and 17 females) withcervical ossification of the posterior longitudinal ligament up to C2 which causedcompression symptoms were operated with posterior cervical surgery in ourhospital from January 2013 to June 2017.The average age was 55.74+7.91 years old, ranging from 39 to 71 years. Among these patients, 21 patients underwent C2 dome-like expansive laminoplasty and 18 underwent C2 expansive open-door laminoplasty, the patients in both groups underwent the C3-C7 expansive open-door laminoplasty. The preoperative and postoperative Neck Disability Index (NDI), Japanese Orthopedic Association (JOA) score, the xisual analog scale(VAS) and the space available for the spinal cord (SAC) of C2 segment in X-ray were measured and statistically analyzed. Results All patients were followed up, the follow-up time was from 15 to 63 months (mean 42.3±17.7 months). There was no significant difference in the general condition, NDI, JOA score and JOA score improvement rate between preoperative and postoperative follow-up in 2 groups. There were significant differences in the NDI, JOA, VAS and SAC between preoperative and postoperative follow-up in 2 groups. The VAS score in C2 dome-like expan-sive laminoplasty group 1.52±1.2 was significantly lower than that in C2 expansive open-door laminoplasty group 2.06±0.87(t=-2.23, P<0.05), while the SAC in C2 expansive open-door laminoplasty group 14.11±1.023 was significantly higher than that in C2 dome-like expansive laminoplasty group 11.86±1.014(t=-6.89, P<0.05). No failure of internal fixation or recurrent compres-sion was found during follow-up. Conclusion For patients with ossification of posterior longitudinal ligament up to C2 or higher level, both C2 dome-like expansive laminoplasty and C2 expansive open-door laminoplasty can achieve good results. The SAC in C2 expansive open-door laminoplastygroup was superior to that in C2 dome-like expansive laminoplasty group, while the postoperative pain was more obvious. There was no significant difference in postoperative neurological recovery between the two groups. Using C2 dome-like expansive laminoplasty could reduce postoperative axial pain than the C2 expansive open-door laminoplasty surgery. For patients withossified tissue in the spinal canal, which occupies more than 50% of the sagittal diameter of the spinal canal, or with developmental spinal stenosis, C2 expansive open-door laminoplasty may berecommend to get more adequate decompression. Key words: Cervical vertebrae; Ossification of posterior longitudinal ligament; Axis; Decompression, surgical

Opendoor laminoplasty is good Surgical treatment for multilevel cervical spinal canal stenosis

Background : Expansive open-door laminoplasty is widely accepted as a reliable procedure for cervical myelopathy. However, one acknowledged complication is spring-back complication or closure of the door which may result in re-stenosis of cervical canal and neurologic deterioration. The study aimed for addressing our cervical open-door laminoplasty technique with plate and screw and subsequently the follow-up outcomes.Methods: Thirty consecutive patients who underwent open-door laminoplasty with the novel technique were included and followed for minimum 5 years from July 2011 to June 2016. Antero-posterior diameter (APD) of the vertebral canal of C4 was measured in lateral cervical radiographs. Neurologic scenarios were assessed using the Japanese Orthopaedic Association (JOA) scores.Results: Twenty-five males (83.3%) and five (16.7%) females with an average follow-up of 68 months were enrolled. The preoperative APD was 13.22 mm (±1.15), whereas the postoperative APD increased to 31.23 mm (±2.43) with an expansion ratio of 136.23% (P &lt; 0.05). The JOA score increased from 8.5 preoperatively to 13.45 postoperatively with a recovery rate of 58.2% (P &lt; 0.05). The elevated laminas were maintained open during the follow-up period.Conclusions: Our technique with plate and screw for laminoplasty is a simple and efficient method for maintaining the decompression of cervical canal and neurologic improvement.TAJ 2016; 29(1): 33-38

Comparison of anchor screw fixation versus mini-plate fixation in unilateral expansive open-door laminoplasty for the treatment of multi-level cervical spondylotic myelopathy

Study design:Systematic review and meta-analysis.Background:Anchor screw fixation and mini-plate fixation are widely used in unilateral open-door laminoplasty. There is a great controversy over the preferred fixation method. The purpose of this study is to evaluate the clinical outcomes between anchor screw fixation and mini-plate fixation for the treatment of multilevel cervical spondylotic myelopathy (MCSM).Methods:Related studies that compared the clinical effectiveness of anchor screw fixation and mini-plate fixation in cervical laminoplasty for the treatment of MCSM were acquired by a comprehensive search in PubMed, Embase, the Cochrane library, CNKI, VIP, and WANFANG up to March, 2018. Included studies were evaluated according to eligibility criteria. The main end points included: preoperative Japanese Orthopedic Association (JOA) scores, postoperative JOA scores, JOA scores improvement rate, preoperative and postoperative cervical range of motion (ROM), preoperative and postoperative cervical curvature index (CCI), lamina open angle, operation time, blood loss, C5 nerve palsy rate and axial symptoms rate.Results:Papers in English and Chinese were searched for the initial review, but only 12 articles in Chinese were included in this meta-analysis. All of the selected studies were of high quality as indicated by the Newcastle–Ottawa scale (NOS). Among 809 patients, 372 underwent anchor screw fixation and 437 underwent mini-plate fixation. The results of this meta-analysis indicated that no significant difference was found in preoperative JOA score, JOA scores improvement rate, preoperative CCI, preoperative ROM, C5 palsy rate and blood loss. However, compared with mini-plate fixation, anchor screw fixation patients showed higher axial symptoms rate [RR = 1.75, 95% CI (1.31, 2.35), P <.05], lower postoperative JOA scores [SMD = −0.38, 95% CI (−0.62, −0.15), P <.05], lower postoperative CCI [SMD = −0.64, 95% CI (−0.94, −0.33), P <.05], lower postoperative ROM [SMD = −1.11, 95% CI (−2.18, −0.04), P <.05], smaller lamina open angle [SMD = −1.98, 95% CI (−3.71, −0.24), P <.05], shorter operation time [SMD = −0.33, 95% CI (−0.59, −0.07), P <.05].Conclusions:Compared with anchor screw fixation, mini-plate fixation in cervical laminoplasty appears to achieve better clinical and radiographic outcomes with fewer surgical complications. However, future well-designed, randomized controlled trials are still needed to further confirm our results.

Novel Hybrid Hydroxyapatite Spacers Ensure Sufficient Bone Bonding in Cervical Laminoplasty.

Study DesignProspective observational study.PurposeThis prospective analysis aimed to evaluate the efficacy and bone-bonding rate of hybrid hydroxyapatite (HA) spacers in expansive laminoplasty.Overview of LiteratureVarious types of spacers or plates have been developed for expansive laminoplasty.MethodsExpansive open-door laminoplasty was performed in 146 patients with cervical myelopathy; 450 hybrid HA spacers and 41 autogenous bone spacers harvested from the spinous processes were grafted into the opened side of each lamina. The patients were followed up using computed tomography (CT), and their bone-bonding rates for hybrid HA and autogenous spacers, bone-fusion rates of the hinges of the laminae, and complications associated with the implants were then examined.ResultsClinical symptoms significantly improved in all patients, and no major complications related to the procedure were noted. The hybrid HA spacers exhibited sufficient bone bonding on postoperative CT. The hinges completely fused in over 95% patients within 1 year of the procedure. Only 4 spacers (0.9%) developed lamina sinking, and most expanded laminae maintained their positions without sinking or floating throughout the follow-up period.ConclusionsHybrid HA spacers contributed to high bone-fusion rates of the spacers and hinges of the laminae, and no complications were associated with their use. Cervical laminoplasty with these spacers is safe and simple, and it yields sufficient fixation strength while ensuring sufficient bone bonding during the immediate postoperative period.