Cervical Expansive Open-door Laminoplasty Research Articles

Biomechanical study of the stability of posterior cervical expansive open-door laminoplasty combined with bilateral C4/5 foraminotomy and short-segment lateral mass screw fixation: a finite element analysis

BackgroundPosterior cervical expansive open-door laminoplasty (EODL) may cause postoperative C5 palsy, and it can be avoided by EODL with bilateral C4/5 foraminotomy. However, prophylactic C4/5 foraminotomy can compromise cervical spine stability. To prevent postoperative C5 palsy and boost cervical stability, We propose a new operation method: EODL combined with bilateral C4/5 foraminotomy and short-segment lateral mass screw fixation. However, there are no studies on the biomechanical properties of this surgery.PurposeEvaluating the biomechanical characteristics of EODL combined with bilateral C4/5 foraminotomy and short-segment lateral mass screw fixation and other three classic surgery.MethodsAn original model (A) and four surgical models (B-E) of the C2-T1 vertebrae of a female patient were constructed. (B) EODL; (C) EODL combined with bilateral C4/5 foraminotomy; (D) C3-6 expansive open-door laminoplasty combined with bilateral C4/5 foraminotomy and short-segment lateral mass screw fixation; (E) C3-6 expansive open-door laminoplasty combined with bilateral C4/5 foraminotomy and C3-6 lateral mass screw system. To compare the biomechanical properties of cervical posterior internal fixation; (E) C3-6 expansive open-door laminoplasty combined with bilateral C4/5 foraminotomy and C3-6 lateral mass screw system. To compare the biomechanical properties of cervical posterior internal fixation methods, six physiological motion states were simulated for the five models using a 100N load force and 1.5Nm torque. The biomechanical advantages of the four internal fixation systems were evaluated by comparing the ranges of motion (ROMs) and maximum stresses.Results The overall ROM of Model C outperformed the other four models, reaching a maximum ROM in the extension state of 10.59°±0.04°. Model C showed a significantly higher ROMs of C4/5 segment than other four models. Model D showed a significantly lower ROM of C4/5 segment than both Model B and Model C. Model E showed a significantly lower ROM of C4/5 segment than Model D. The stress in the four surgical models were mainly concentrated on the internal fixation systems.ConclusionEODL combined with bilateral C4/5 foraminotomy and short-segment lateral mass screw fixation can maintain the stability of the spine and has minimal effects on the patient’s cervical spine ROMs in the extension and flexion state. As a result, it may be a promising treatment option for cervical spondylotic myelopathy (CSM) to prevention of postoperative C5 palsy.

A Novel Classification of Cervical Spine Trauma in Ankylosing Spondylitis and Corresponding Surgical Outcomes

Currently, there are no reports on the specific classification of cervical spine trauma (CST) in ankylosing spondylitis (AS) based on the trauma mechanism. In this study, we aimed to describe a novel classification of CST in AS with more details, and put forward the corresponding surgical outcomes related to different types, hoping to provide a practical reference for clinical decision-making and academic communication. From January 2008 to December 2021, AS patients who experienced CST were retrospectively reviewed and included. Clinical data including gender, age, reason of trauma, time interval between AS diagnosis and trauma were collected. The American Spinal Injury Association (ASIA) grade system was used to describe patients' neurological status. Based on the combination of surgical experience and follow-up observation, the lower cervical spine trauma in AS patients was divided into three main types, namely single level fracture-dislocation (type 1), spinal cord injury without fracture-dislocation (type 2), and Andersson lesion (type 3). Furthermore, we performed detailed subtypes according to whether cervical spine was completely fused and the location of injury. Meanwhile, according to different approaches, surgical methods mainly included Anterior Cervical Discectomy and Fusion (ACDF), Anterior Cervical Corpectomy and Fusion (ACCF), Posterior Expansive Open-door Cervical Laminoplasty (PEOLP), Posterior Cervical Laminectomy Decompression and Fusion (PCLDF), and their combination. Postoperative general and surgery-related complications were also recorded. A total of 102 patients were enrolled, including 91 males and 11 females, with an average age of 51.9 years. Their average interval time between AS diagnosis and injury was 27.8 years. Patients with high-energy and low-energy trauma were 54 and 48 respectively. There were 79 patients suffering spinal cord nerve impairment after trauma. With regard to the distribution of different types, the number of patients in type 1, type 2, and type 3 were 86, 14, and two, respectively. For different types, PCLDF was the most commonly used surgical method, accounting for 55.9%, while ACCF was only applied for one time. In type 1, the frequencies of ACDF, ACCF, PCLDF, and ACDF+PCLDF were 10.5%, 1.2%, 55.8%, and 32.5%. In type 2, the frequencies of ACDF, PCLDF, ACDF+PCLDF, and PEOLP were 7.1%, 50.0%, 7.1%, 35.8%. Postoperatively, 21 patients achieved neurological function improvement. The incidences of general and surgery-related complications were 19.6% and 5.9%, respectively. All patients achieved bone fusion and durable decompression at the last follow-up. Our novel classification could enrich the scope of CST in AS patients and provide valuable references to the corresponding clinical management. Besides, there are strict indications of different surgical methods, factors like patient's physical condition, trauma type, surgical purpose, and expected efficacy were all required to consider before making a clinical decision.

Extension of decompression to C2 doesn’t affect the spinal sagittal parameters compared with standard open-door laminoplasty

We modified and extended laminoplasty to the upper cervical spine on patients with canal stenosis associated with upper cervical spinal ossified lesions. However, whether the extended decompression range of laminoplasty can cause further effects on cervical stability is rarely studied at present. A retrospective study to analyze the relationship between the surgical levels and cervical sagittal parameters effects was performed in patients with cervical spondylosis myelopathy who had undergone posterior cervical expansive open-door laminoplasty with/without extending to C2. In total, 64 patients were divided into 2 groups according to the surgical levels. Radiologic outcomes of occipito-cervical angle (C0-2 Cobb angle), CL C27 Cobb angle, cervical sagittal vertical alignment, T1-Slope (T1S), T1S minus CL (T1S-CL), spino-cranial angle and center of the sella turcica-C7 SVA (St-SVA) were evaluated on lateral X-rays of the cervical spine at pre-operation, post-operation, and 2-year follow-up. The patient's health-related quality of life was obtained including neck disability index, Japanese orthopaedic association scores, and visual analog scale. Changes in sagittal parameters were observed in both groups after surgery. T1S, cervical sagittal vertical alignment, and T1S-CL significantly increased and CL decreased in 2 groups of patients postoperative. After a 2-year follow-up period, the C0-2 Cobb angle was found to increase compared to preoperative records. In addition, there were no significant differences in spino-cranial angle and st-SVA between preoperative and 2 years follow-up measurements. Health-related quality of life was improved in both groups and was not significantly different. Herein, the parameters indicated a tilting forward of the lower cervical spine and a more lordotic upper cervical spine to maintain a horizontal gaze in patients. However, C2 to 7 laminoplasty was performed to achieve satisfactory clinical results without significantly changing the spinal sagittal parameters.

Comparison of blood loss between tranexamic acid-soaked absorbable Gelfoam and topical retrograde injection via drainage catheter plus clamping in cervical laminoplasty surgery

BackgroundTo compare the safety and efficacy of tranexamic acid (TXA)-soaked absorbable Gelfoam and the retrograde injection of TXA through a drain with drain-clamping in degenerative cervical laminoplasty patients.MethodsPatients were assigned into either TXA retrograde injection (TXA-RI), TXA-soaked absorbable Gelfoam (TXA-Gel), or control groups. The demographics, operative measurements, volume and length of drainage, length of hospital stay, complete blood cell count, coagulopathy, postoperative complications, and blood transfusion were recorded.ResultsWe enrolled 133 patients, with 44, 44, and 45 in the TXA-RI, TXA-Gel, and control groups, respectively. The baseline characteristics did not differ significantly among the three groups. The TXA-RI group exhibited a lower volume and length of postoperative drainage compared to the TXA-Gel and control groups (126.60 ± 31.27 vs. 156.60 ± 38.63 and 275.45 ± 75.27 mL; 49.45 ± 9.70 vs 58.70 ± 10.46 and 89.31 ± 8.50 hours, all P < 0.01). The TXA-RI group also had significantly shorter hospital stays compared to the control group (5.31 ± 1.18 vs 7.50 ± 1.25 days, P < 0.05) and higher hemoglobin and hematocrit levels (12.58 ± 1.67 vs 11.28 ± 1.76 g/dL; 36.62 ± 3.66% vs 33.82 ± 3.57%, both P < 0.05) at hospital discharge. In the TXA-RI and TXA-Gel groups, the D-dimmer (DD) and fibrinogen (FIB) were significantly lower than those in the control group after surgery (P < 0.05). None of the patients required blood transfusion. No complications, including thromboembolic events, were reported.ConclusionTopical retrograde injection of TXA through a drain with drain-clamping at the conclusion of unilateral posterior cervical expansive open-door laminoplasty may effectively reduce postoperative blood loss and the length of hospital stays without increasing postoperative complications.

Effect of modified lateral mass screws implantation strategy on axial symptoms in cervical expansive open-door laminoplasty

To investigate the effect of modified lateral mass screws implantation strategy on axial symptoms in cervical expansive open-door laminoplasty. A clinical data of 166 patients, who underwent cervical expansive open-door laminoplasty between August 2011 and July 2016 and met the selection criteria, was retrospective analyzed. Among them, 81 patients were admitted before August 2014 using the traditional mini-plate placement and lateral mass screws implantation strategy (control group), and 85 patients were admitted after August 2014 using modified lateral mass screws implantation strategy (modified group). There was no significant difference in the gender composition, age, clinical diagnosis, disease duration, diseased segment, and preoperative Japanese Orthopaedic Association (JOA) score, pain visual analogue scale (VAS) score, Neck Disability Index (NDI), cervical curvature and range of motion, spinal canal diameter and cross-sectional areas, and Pavlov's value between the two groups ( P>0.05). The operation time, intraoperative blood loss, the number of facet joints penetrated by lateral mass screws, effectiveness evaluation indexes (JOA score and improvement rate, VAS score, NDI), imaging evaluation indexes (cervical curvature and range of motion, spinal canal diameter and cross-sectional areas, Pavlov's value, and lamina open angle), and complications were recorded and compared between the two groups. The modified group had shorter operation time and lower intraoperative blood loss than the control group ( P<0.05). There were 121 (29.9%, 121/405) and 10 (2.4%, 10/417) facet joints penetrated by lateral mass screws in control and modified groups, respectively; and the difference in incidence was significant ( χ 2=115.797, P=0.000). Eighteen patients in control group had 3 or more facet joints penetrated while no patients in modified group suffered 3 or more facet joint penetrated. The difference between the two groups was significant ( P=0.000). All patients were followed up, the follow-up time was (28.7±4.9) months in modified group and (42.4±10.7) months in control group, showing significant difference ( t=10.718, P=0.000). The JOA score, VAS score, and NDI at last follow-up of the two groups were significantly improved compared with preoperative ( P<0.05); there was no significant difference in JOA score and improvement rate and VAS score between the two groups ( P>0.05), but the NDI was significantly lower in modified group than in control group ( P<0.05). There were significant differences in cervical curvature and range of motion, spinal canal diameter, Pavlov's value, and cross-sectional areas at last follow-up when compared with those before operation in both groups ( P<0.05). There was no significant difference in the above indicators and lamina open angle between the two groups ( P>0.05). The modified group has a relative lower axial symptom rate (23/85, 27.1%) than the control group (27/81, 33.3%), but the difference was not significant ( Z=-1.446, P=0.148). There was no significant differences between the two groups in the incidences of C 5 nerve root palsy, cerebrospinal fluid leakage, wound infection, and lung or urinary tract infection ( P>0.05). In the cervical expansive open-door laminoplasty, the modified lateral mass screws implantation strategy can effectively reduce the risk of lateral mass screw penetrated to the cervical facet joints, and thus has a positive significance in avoiding the axial symptoms caused by facet joint destruction.

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.

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.

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.

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.

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.

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.

Risk Factors for Significant Intraoperative Blood Loss During Unilateral Expansive Open-Door Cervical Laminoplasty for Cervical Compressive Myelopathy

Unilateral expansive open-door cervical laminoplasty is an effective and safe procedure for cervical compressive myelopathy but occasionally is accompanied with significant intraoperative blood loss (SIBL). The aim of the present study was to elucidate the risk factors for SIBL in patients undergoing cervical laminoplasty for multilevel cervical compressive myelopathy and to identify the effect of SIBL on neurologic complications. A total of 215 patients who received cervical laminoplasty between January 2010 and August 2016 were enrolled in the study. SIBL was defined as 500 mL or more of blood volume during surgery. Patients were subdivided into 2 groups according to whether they suffered from SIBL (n= 26) or not (n= 189). Patient characteristics and clinical data were collected. Univariate and multivariable analysis were performed to identify independent risk factors for SIBL. The incidence of SIBL during unilateral expansive open-door cervical laminoplasty was 12.1%. The multivariable logistic regression analysis showed Pavlov ratio (odds ratio [OR] 0.002, P= 0.009), ossification of the posterior longitudinal ligament (OR 2.677, P= 0.038), and number of complete hinge fractures (OR 1.842, P= 0.015) were independent risk factors for SIBL during cervical laminoplasty. Patients with SIBL during cervical laminoplasty had a greater rate of neurologic complications during hospitalization (P= 0.012), worse neurologic recovery rate at discharge (P= 0.01), and longer postoperative length of stay (P= 0.003). This study suggested that Pavlov ratio, ossification of the posterior longitudinal ligament, and number of complete hinge fractures were independent risk factors for SBIL during cervical laminoplasty. SIBL in cervical laminoplasty was associated with greater neurologic complications and worse neurologic functional recovery.

Analysis of clinical effects of absorbable hemostatic fluid gelatin and absorbable gelatin sponge on the hemostasis during operation of unilateral open-door cervical expansive laminoplasty

To compare the hemostatic effect between absorbable hemostatic fluid gelatin (HFG) and absorbable gelatin sponge(GS) during operation of unilateral open-door cervical expansive laminoplasty. The clinical data of 83 patients underwent unilateral open-door cervical expansive laminoplasty from February 2014 to May 2016 were retrospectively analyzed. According to the used hemostatic materials, patients were divided into two groups. In HFG group, there were 30 males and 11 females, ranging in age from 29 to 81 years, with an average of(55.6±11.6)years; 14 cases were simple cervical spinal stenosis, 9 were cervical spinal stenosis and ossification of posterior longitudinal ligament, and 18 were cervical spinal stenosis complicated with multiple cervical disc herniation. And in GS group, there were 32 males and 10 females, ranging in age from 36 to 78 years, with an average of (55.4±11.1) years; 12 cases were simple cervical spinal stenosis, 10 were cervical spinal stenosis complicated with ossification of posterior longitudinal ligament, and 20 were cervical spinal stenosis complicated with multiple cervical disc herniation. There was no significant difference in the age, gender, and disease categories of patients between two groups (P>0.05). The operative time, intraoperative bleeding, postoperative drainage, and postoperative complications were compared between two groups. The average operative time, intraoperative bleeding, and postoperative drainage in HFG group were(137.2±30.0) min, (156.1±74.6) ml, and (212.1±67.6) ml, respectively; and in GS group were (154.8±33.5) min, (242.9±120.7) ml, and(303.3±115.5) ml, respectively. There were significantly differences in above items between two groups(P<0.05). No acute heamatoma or related complications was found postoperatively. Compared with GS, HFG can obviously decrease operative time, intraoperative bleeding, and postoperative drainage. It is a safe and effective hemostatic material for the operation of unilateral open-door cervical expansive laminoplasty.

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

Multivariate analysis of factors associated with kyphotic deformity after laminoplasty in cervical spondylotic myelopathy patients without preoperative kyphotic alignment

The risk factors of post-laminoplasty kyphosis in patients with cervical spondylotic myelopathy (CSM) without preoperative kyphotic alignment are not well known. This study aimed to compare clinical and radiological data between patients with or without post-laminoplasty kyphosis and to investigate the factors associated with post-laminoplasty kyphosis in CSM patients without preoperative kyphotic alignment. Patients (n = 194) who received unilateral expansive open-door cervical laminoplasty with miniplate fixation and completed a 1-year follow-up were enrolled. Patients were grouped according to whether they suffered from postoperative kyphosis (P) or not (NP). Postoperative kyphosis was observed in 21 (10.8%) patients. The recovery rates of the Japanese Orthopaedic Association scores at the 1-year follow-up in the P group were inferior to those in the NP group (31.9% vs. 65.2%, P < 0.001). Logistic regression with post-laminoplasty kyphosis as the dependent variable showed independent risks associated with an increased C2–7 sagittal vertical axis (SVA, odds ratio [OR] = 1.085, 95% confidence interval [CI] = 1.025–1.203, P = 0.015), destroyed facet joints (OR = 1.132, 95% CI = 1.068–1.208, P < 0.001), and cephalad vertebral level undergoing laminoplasty (CVLL, OR = 2.860, 95% CI = 1.164–6.847, P = 0.021). These findings suggest that CVLL, C2–7 SVA, and destroyed facet joints are associated with kyphosis after laminoplasty in CSM patients without preoperative kyphotic alignment.

Effect of Mini-plate Fixation on Hinge Fracture and Bony Fusion in Unilateral Open-door Cervical Expansive Laminoplasty

Study Design: This was a retrospective study. Objective: The aim of this study was to investigate the effect of Centerpiece mini-plate fixation on the complete fracture and bony fusion of the hinge side in unilateral open-door cervical expansive laminoplasty. Summary of Background Data: Cervical laminoplasty is an effective and safe surgery for cervical canal stenosis. The Centerpiece mini-plate is an instrument used to secure the laminae and maintain the cervical canal expansion. Stability of the new laminae is largely dependent on healing of the hinge side bone fracture and the degree of bony fusion. To date, few studies have reported on the effects of mini-plate fixation on these 2 important factors. Materials and Methods: Between September 2009 and March 2011, 58 patients received unilateral open-door cervical expansive laminoplasty at the authors’ hospital. The group included 47 male and 11 female patients, with a mean age of 61 (range, 35–81) years. Two hundred twenty-five laminae were fixed using the Centerpiece mini-plate (group A), whereas 62 laminae were fixed using suture suspension (group B). The rates of fracture and bony fusion of the hinge were observed using computed tomography scan and compared between the 2 groups. The complete fractures were subdivided into 4 groups based on the degree of displacement of the fractured ends: type I (no displacement), type II (mild to moderate displacement), type III (complete displacement or separation), or type IV (the hinge had collapsed into the cervical canal). Results: The number of incomplete fractures and type I to IV fractures in group A were 95, 93, 25, 8, and 4 and 29, 25, 4, 2, 2 in group B, respectively. There were no significant differences between the 2 groups in terms of complete fracture rates (P=0.309) and complete fracture type distribution (P=0.694). Group A had a significantly higher rate of bony fusion of the hinge 3 months after surgery (82% vs. 70%, P=0.042); however, this rate was not statistically significant 6 months after surgery (P=0.141). For type I complete hinge fracture, group A had higher bony fusion rates, both 3 months (86% vs. 57%, P=0.004) and 6 months (92% vs. 85%, P=0.048) postoperatively. The rates of bony fusion were also significantly different among all complete fracture types 3 months (P&lt;0.001) and 6 months (P&lt;0.001) postoperatively. Conclusions: Centerpiece mini-plate fixation in unilateral open-door cervical expansive laminoplasty might not increase the complete fracture rate compared with suture suspension and might promote bony fusion of type I complete hinge fractures.

Multivariate Analysis of Factors Associated With Axial Symptoms in Unilateral Expansive Open-Door Cervical Laminoplasty With Miniplate Fixation.

Retrospective case–control study.Unilateral expansive open-door cervical laminoplasty with miniplate fixation is an efficient and increasing popular surgery for multilevel cervical spondylotic myelopathy. Axial symptoms are the most frequent complaints after cervical laminoplasty. But the mechanisms have not been fully clarified yet.The objective of this study is to compare the clinical and radiologic data between patients with or without axial symptoms and to investigate the factors associated with axial symptoms by multivariate analysis in cervical laminoplasty with miniplate fixation.A total of 129 patients who underwent cervical laminoplasty with miniplate fixation were comprised from August 2009 to March 2014. Patients were grouped according to whether they suffered from postoperative axial symptoms (PA) or not (NA). The clinical data including gender, age, duration of symptoms, diagnosis type, medical comorbidity, operative level, blood loss, operative time, pre- and post-Japanese Orthopedic Association (JOA) score, JOA recovery rates, and other complications were recorded. The radiologic data including cervical canal diameter, C2–7 Cobb angle, cervical range of motion (ROM), cross-sectional area, open angle, hinge union, and facet joint destroyed would be measured according to X-ray plain and CT scan images. The univariate analysis and multivariate logistic regression analysis were performed.There were 39 patients in PA group and 90 patients in NA group. Both groups gained significant JOA improvement postoperatively (P < 0.05). The preoperative neck pain (P = 0.048), negative change of cervical ROM (P = 0.018), and facet joints destroyed (P = 0.022) were significant different between the 2 groups. There were no significant differences for other clinical and radiography parameters between the groups (P > 0.05). The multivariate analysis showed that the negative change of cervical ROM (OR = 1.062, P = 0.047) and facet joints destroyed (OR = 0.661, P = 0.024) were related to axial symptoms.The change of cervical ROM and facet joints destroyed by miniscrews might be associated with axial symptoms after cervical laminoplasty with miniplate fixation. Cervical spine surgeons should carefully operate to decrease the injury of posterior musculature structure and protect the facet joints.

Expansive Open-Door Cervical Laminoplasty: In Situ Reconstruction of Extensor Muscle Insertion on the C2 Spinous Process Combined With Titanium Miniplates Internal Fixation.

Retrospective cohort study.To evaluate efficacy and relevant problems of in situ reconstruction of extensor muscle insertion on the C2 spinous process combined with titanium miniplates internal fixation in expansive open-door cervical laminoplasty in order to improve surgical treatment effect.Expansive open-door cervical laminoplasty has been widely applied in clinical practice, but there are a series of postoperative problems. Therefore, decreasing postoperative complications in order to more effectively relieve symptoms remains a subject for additional research.From October 2011 to September 2013, a total of 60 patients who suffered cervical canal stenosis were treated by expansive open-door laminoplasty with in situ reconstruction of extensor muscle insertion on the C2 spinous process combined with titanium miniplates internal fixation. Changes of cervical curvature index (CI) and range of motion (ROM) were calculated using data from preoperative and postoperative cervical spine X-ray examinations. Clinical function was scored using the Japanese Orthopedics Association Scoring System (JOA) and the neck disability index (NDI).The mean CI before the operation and at 1-year postoperation were 10.49% ± 3.93% and 14.14 ± 2.85 (P < 0.05). The mean ROM values were 43.35 ± 7.55 before the operation, 34.83 ± 7.41 at 1-year postoperation (P < 0.05). The NDI scores decreased from 19.42 ± 4.12 to 7.37 ± 2.58, and the JOA scores increased from 8.87 ± 1.99 to 13.55 ± 1.72, representing significant improvement (P < 0.05). One patient had postoperative C5 nerve root palsy and completely recovered 1 month later. Neither collapse nor door closure in the open-door side occurred in any of the patients.Expansive open-door cervical laminoplasty with in situ reconstruction of extensor muscle insertion on the C2 spinous process combined with titanium miniplates internal fixation is a safe and effective surgical method, and can effectively decrease postoperative complications and achieve satisfactory clinical results.