Cervical Open-door Laminoplasty Research Articles

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.

Relationship between the laminoplasty opening size and the laminoplasty opening angle, increased sagittal canal diameter and the prediction of spinal canal expansion following open-door cervical laminoplasty.

To clarify the relationship between the laminoplasty opening size (LOS), the laminoplasty opening angle (LOA) and the increase in sagittal canal diameter (SCD) and to predict the amount of canal enlargement during open-door cervical laminoplasty (ODCL). Formula describing the relationship between LOS and LOA, the increase in SCD was deduced. The parameters of pre- and postoperative computed tomography scans of 36 patients who had undergone laminoplasty surgery were measured by picture archiving and communication system (PACS) software, and the amount of canal enlargement of these patients was predicted when the opening size of laminoplasty was 8, 10, 12, 14 and 16 mm according to the formula. For equivalent LOS, the amount of canal enlargement with each opening size differed throughout the cervical region. When the C3-C7 LOS was 10 mm the SCD increased >4.1 mm, and the canal area increased in C3-C6 >88 mm(2), and the canal area increased in C7 > 80 mm(2). When the C3-C7 LOS was 12 mm, the SCD increased >5.2 mm, and the canal area increased in C3-C6 >104 mm(2), and the canal area increased in C7 > 94 mm(2). Formula accurately showed the relationship between the LOS and the increase in SCD achieved by ODCL. The amount of canal enlargement following ODCL could be predicted by the formula. LOS of 10-12 mm at C3-C7 might be optimal during ODCL.

Cervical open-door laminoplasty technique with simple sutures and bone grafts: a single institutional study with 30 consecutive cases.

BackgroundExpansive 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 restenosis of cervical canal and neurologic deterioration. The study aimed for addressing our cervical open-door laminoplasty technique with sutures and bone grafts and subsequently the follow-up outcomes.MethodsThirty consecutive patients who underwent open-door laminoplasty with the novel technique were included and followed for minimum 5 years from Jan 2006 to Dec 2007. Anteroposterior diameter (APD) of the vertebral canal of C4 was measured in lateral cervical radiographs. Neurologic scenarios were noted using the Japanese Orthopaedic Association (JOA) scores.ResultsTwenty-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 < 0.05). The JOA score increased from 8.5 preoperatively to 13.45 postoperatively with a recovery rate of 58.2% (P < 0.05). The elevated laminas were maintained open during the follow-up period.ConclusionsOur technique with sutures and bone graft for laminoplasty is a simple and efficient method for maintaining the decompression of cervical canal and neurologic improvement.

Modified Open-Door Laminoplasty Using a Ceramic Spacer and Suture Fixation for Cervical Myelopathy.

PurposeTo introduce a new simple technique using suture anchors and ceramic spacers to stabilize the elevated laminae in open-door cervical laminoplasty. Although ceramic spacers were placed in the opened laminae and fixed with nylon threads in this series, it was occasionally difficult to fix the nylon threads to the lateral mass.Materials and MethodsStudy 1: A preliminary study was conducted using a suture anchor system. Sixteen consecutive patients who underwent surgery for cervical myelopathy were prospectively examined. Study 2: The second study was performed prospectively to evaluate the feasibility of this new technique based on the result of the preliminary study. Clinical outcomes were examined in 45 consecutive patients [cervical spondylotic myelopathy (CSM)] and 43 consecutive patients (OPLL). The Japanese Orthopedic Association scoring system (JOA score), axial neck pain, and radiological findings were analyzed.Results1) In one case, re-operation was necessary due to dislodgement of the ceramic spacer following rupture of the thread. 2) In all patients, postoperative CT scans showed that the anchors were securely inserted into the bone. In the CSM group, the average JOA score improved from 9.5 points preoperatively to 13.3 at follow-up (recovery 51%). In the OPLL group, the average JOA score improved from 10.1 (5-14) points preoperatively to 14.4 (11-16) at follow-up (recovery 62%). There were no serious complications.ConclusionThe use of the suture anchor system made it unnecessary to create a hole in the lateral mass and enabled reliable and faster fixation of the HA spacers in open-door laminoplasty.

All levels versus alternate levels plate fixation in expansive open door cervical laminoplasty.

Background:Expansive open door laminoplasty with the use of titanium miniplate is becoming popular. Usually, the plate is applied at each level to prevent re-closure of the opened lamina. However, it is also used at alternating levels (i.e., C3, C5 and C7) in clinical settings in order to reduce the cost. Whether they have any difference in clinical efficacy? There is a lack of comparative data between the two kinds of plate fixation in the literature.Materials and Methods:83 patients who underwent cervical laminoplasty with alternating levels plate fixation (51 patients in Group A) or all levels plate fixation (32 patients in Group B) between January 2008 and October 2012 were evaluated in our institute retrospectively. Clinical and radiologic outcomes were assessed.Results:No statistical difference was found in the mean operation time, blood loss, incidence of significant axial symptoms and C5 palsy, preoperative anteroposterior diameter (APD) and preoperative Japanese Orthopedic Association score between the two groups. However, Group B showed a higher rate of neurologic recovery after surgery. Postoperative increased APD and open angle in Group B were significantly larger than Group A. The mean cost for Group B (12801 ± 460.6 USD) was higher than Group A (8906 ± 566.7 USD).Conclusions:Despite the higher cost of all level fixation, it is more effective in maintaining the expansion of the spinal canal and can obtain better clinical improvement compared to alternating levels fixation.

Two-Year Clinical and Radiological Outcomes of Open-Door Cervical Laminoplasty With Prophylactic Bilateral C4–C5 Foraminotomy in a Prospective Study

A prospective study. To evaluate the 2-year outcomes of open-door cervical laminoplasty with prophylactic bilateral C4-C5 foraminotomy. A prospective trial of prophylactic bilateral C4-C5 foraminotomy with open-door laminoplasty for cervical compression myelopathy showed a significant efficacy for preventing postoperative C5 palsy. However, in bilateral foraminotomy, there are concerns such as postoperative instability, hinge fracture, or nonunion, which may cause deterioration of neurological symptoms and neck pain. A prospective trial was performed in 141 patients between 2009 and 2010 (group F). A group of 141 patients who underwent open-door laminoplasty without prophylactic foraminotomy from 2006 to 2008 served as a control group (group NF). Here, we report 2-year radiological and clinical data for 121 patients (follow-up rate: 85.8%) in group F and 115 patients (81.6%) in group NF. The 2 groups were demographically similar, except for the operation time. In group F, the mean rate of facet joint preservation was 71.4%. C2-C7 and C4-C5 lordosis and C4 translational movement were maintained postoperatively in both groups. The range of motion of C2-C7 and C4-C5 significantly decreased to about 80% of the preoperative values in both groups (P < 0.01). These radiological parameters and the incidence of hinge fracture and nonunion did not differ significantly between the groups. Visual analogue scale scores for neck pain were unchanged and significant recoveries (P < 0.001) in Japanese Orthopaedic Association scores were found in both groups. There were no significant differences in these clinical scores between the groups. The incidences of C5 palsy were 1.7% and 7.0% in groups F and NF, respectively (P = 0.043). Prophylactic bilateral C4-C5 foraminotomy did not adversely affect the 2-year radiological and clinical outcomes. Therefore, we conclude that this approach is an effective and desirable procedure for preventing postoperative C5 palsy. 3.

Hinge Fracture during Cervical Open-door Laminoplasty: Does it Affect Clinical and Radiographic Outcomes?

ObjectiveThe purpose of this study was to determine whether the status of the hinge gutter affected clinical and radiographic outcomes of cervical open door laminoplasty.MethodsWe retrospectively analyzed 43 patients who had undergone cervical open door laminoplasty. 23 CT scans were performed at 2 days post-operation. The number of CT scans at 3, 6, 12 and 24 months were 16, 12, 21 and 11, respectively. We collected perioperative and follow-up data, including clinical and radiographic results.ResultsThere were 7 patients without a hinge fracture and 16 patients with one or more hinge fractures at 2 days postoperation. There were 90 hinges, and the rate of ideal greenstick deformation of the hinge was 63% on 2-day-postoperative CT scans. Postoperative VAS scores of neck pain (p=0.012) in patients without a hinge fracture were higher than in patients with hinge fractures. The hinge healing rates were 37% at 3 months, 57.4% at 6 months, 86.4% at 12 months, and 85.4% at 24 months. Among the patients, 14 patients had healed hinges, and 7 patients had one or more hinge(s) that was/were not healed at 12 months post-operation. However, in clinical and radiographic outcomes, there was no difference between these patients.ConclusionCervical open door laminoplasty was safe and provided stable reconstruction of laminar expansion. In radiographs, the difference between hinges that had healed and hinges that had not healed was statistically negligible. Hinge fractures might not influence the clinical and radiographic outcomes of cervical open door laminoplasty.

Delayed hinge fracture after plate-augmented, cervical open-door laminoplasty and its clinical significance

Background contextAmong the various forms of laminoplasty fixation, plate augmentation provides a semirigid arch reconstruction and is gaining popularity as the result of its safety and effectiveness. However, the effects of this procedure on hinge status and subsequent bony healing remain unclear. PurposeWe sought to evaluate the status and time course of bony healing of the hinge gutter and to determine the effect on postoperative clinical course of plate-only, open-door cervical laminoplasty. Study designThis was a retrospective clinical series. Patient sampleA total of 79 adult men and women undergoing cervical laminoplasty in a university hospital setting were studied. Outcome measuresTime-dependent changes in hinges observed on computed tomography (CT) were used to measure the radiological outcome. A numerical rating scale of axial neck pain and arm pain was used to evaluate the clinical outcome. MethodsPatients who underwent plate-only, open-door laminoplasty for cervical myelopathy and had available postoperative CT scans were enrolled in this study. Neck pain intensity before and 1 year after surgery was assessed with questionnaires. CT scans (n=125) obtained after surgery were assessed in terms of bony healing of the hinge. ResultsMost of the hinges were initially well-bent. Only 9% were found to be “fractured” or “in danger of fracture” at 1 week. Primary healing without callus formation, which is the next step of bony healing of well-bent hinges, was observed in 62% of cases at month 4. The remaining 38% were classified as “fractured” or in the process of “secondary healing.” A similar number of hinges was classified as “secondarily healed” after 1 or 2 years of follow-up. All except one hinge were well united and incorporated at the final follow-up, and the number of hinges classified as “fractured or secondarily healed” related to postoperative axial neck pain with respect to the 1-year visual analog scale for the neck and the Neck Disability Index. ConclusionsAlthough plate-only, open-door laminoplasty is a safe and reliable surgery for decompression of multilevel cervical disease, the fixation that it provides on the open side may not be sufficiently stable to allow successful primary healing. Additional attention should be paid to the hinged side to prevent delayed fracture in the early postoperative period and to reduce postoperative axial pain.

Risk factors associated with upper extremity palsy after expansive open-door laminoplasty for cervical myelopathy

Background contextPostoperative paresis, so-called C5 palsy, of the upper extremities is a common complication of cervical surgery. There have been several reports about upper extremity palsy after cervical laminoplasty for patients with cervical myelopathy. However, the possible risk factors remain unclear. PurposeTo investigate the factors associated with the development of upper extremity palsy after expansive open-door laminoplasty for cervical myelopathy. Study designA retrospective review of medical records. Patient sampleA total of 102 patients (76 men and 26 women) were eligible for analysis in this study. The mean age of the patients was 58.7 years (range 35–81 years). Sixteen patients (13 men and 3 women, average age 62.8 years) with palsy were categorized as Group P, and eighty-six patients (63 men and 23 women, average age 57.8 years) without palsy as Group C. Outcome measuresThe demographic data collected from both groups were age, sex, duration of symptoms, disease, and type of surgical procedure. Cervical curvature index, width of the intervertebral foramen (WIF) at C5, anterior protrusion of the superior articular process (APSAP), number of compressed segments, high–signal intensity zone at the level corresponding to C3–C5 (HIZ:C3–C5), and posterior shift of the spinal cord (PSSC) were also evaluated. MethodsUpper extremity palsy was defined as weakness of Grade 4 or less of the key muscles in the upper extremity by manual muscle test without any deterioration of myelopathic symptoms after surgery. Comparisons were made with screen for the parameters with significant differences, and then we further analyzed these parameters by logistic regression analysis (the forward method) to verify the risk factors of the upper extremity palsy. ResultsSignificant differences in diagnosis, the type of procedure, WIF, APSAP, and HIZ:C3–C5 were observed between the two groups. No statistical difference in PSSC between the groups was noted (2.06 vs. 2.53 mm, p=.247). In logistic regression analysis, ossification of the posterior longitudinal ligament (OPLL), cervical open-door laminoplasty together with posterior instrumented fusion (CLP+PIF), and WIF were found to be significant risk factors for postoperative upper extremity palsy. ConclusionsPatients with preoperative foraminal stenosis, OPLL, and additional iatrogenic foraminal stenosis because of CLP+PIF were more likely to develop postoperative upper extremity palsy. Attention should be given to the WIF determined on preoperative computed tomography of the C5 root. To prevent iatrogenic foraminal stenosis, appropriate distraction between spine segments should be provided during placement of the rod.

Comparative Effectiveness of Different Types of Cervical Laminoplasty

Study Design Systematic review. Study Rationale Numerous cervical laminoplasty techniques have been described but there are few studies that have compared these to determine the superiority of one over another. Clinical Questions The clinical questions include key question (KQ)1: In adults with cervical myelopathy from ossification of the posterior longitudinal ligament (OPLL) or spondylosis, what is the comparative effectiveness of open door cervical laminoplasty versus French door cervical laminoplasty? KQ2: In adults with cervical myelopathy from OPLL or spondylosis, are postoperative complications, including pain and infection, different for the use of miniplates versus the use of no plates following laminoplasty? KQ3: Do these results vary based on early active postoperative cervical motion? Materials and Methods A systematic review of the English-language literature was undertaken for articles published between 1970 and March 11, 2013. Electronic databases and reference lists of key articles were searched to identify studies evaluating (1) open door cervical laminoplasty and French door cervical laminoplasty and (2) the use of miniplates or no plates in cervical laminoplasty for the treatment of cervical spondylotic myelopathy or OPLL in adults. Studies involving traumatic onset, cervical fracture, infection, deformity, or neoplasms were excluded, as were noncomparative studies. Two independent reviewers (A.L.R., J.R.D.) assessed the level of evidence quality using the Grades of Recommendations Assessment, Development and Evaluation system, and disagreements were resolved by consensus. Results We identified three studies (one of class of evidence [CoE] II and two of CoE III) meeting our inclusion criteria comparing open door cervical laminoplasty with French door laminoplasty and two studies (one CoE II and one CoE III) comparing the use of miniplates with no plates. Data from one randomized controlled trial (RCT) and two retrospective cohort studies suggest no difference between treatment groups regarding improvement in myelopathy. One RCT reported significant improvement in axial pain and significantly higher short-form 36 scores in the French door laminoplasty treatment group. Overall, complications appear to be higher in the open door group than the French door group, although complete reporting of complications was poor in all studies. Overall, data from one RCT and one retrospective cohort study suggest that the incidence of complications (including reoperation, radiculopathy, and infection) is higher in the no plate treatment group compared with the miniplate group. One RCT reported greater pain as measured by the visual analog scale score in the no plate treatment group. There was no evidence available to assess the effect of early cervical motion for open door cervical laminoplasty compared with French door laminoplasty. Both studies comparing the use of miniplates and no plates reported early postoperative motion. Evidence from one RCT suggests that earlier postoperative cervical motion might reduce pain. Conclusion Data from three comparative studies are not sufficient to support the superiority of open door cervical laminoplasty or French door cervical laminoplasty. Data from two comparative studies are not sufficient to support the superiority of the use of miniplates or no plates following cervical laminoplasty. The overall strength of evidence to support any conclusions is low or insufficient. Thus, the debate continues while opportunity exists for the spine surgery community to resolve these issues with appropriately designed clinical studies.

Analysis of C5 Palsy After Cervical Open-door Laminoplasty

A retrospective study. To determine the clinical and imaging characteristics of postoperative C5 palsy after cervical open-door laminoplasty. Postoperative C5 palsy is a common complication of cervical laminoplasty, and although there are several hypotheses regarding its etiology, the pathogenesis and preventive measures remain unidentified and many controversies remain. A total of 141 consecutive patients (100 men and 41 women) who had undergone open-door laminoplasty for cervical myelopathy between 2006 and 2009 were included in this study. Postoperative C5 palsy was defined as deltoid muscle weakness of a grade <3 in manual muscle test. The patients were divided into 2 groups: 1 that had experienced C5 palsy (PG; the palsy group) and the other that had not (NPG; the nonpalsy group). The parameters evaluated were the incidence of C5 palsy, the level at which spinal cord compression appeared preoperatively, the spinal cord level showing a T2 high-signal intensity lesion on magnetic resonance imaging, T2 high-signal intensity lesions newly appearing postoperatively, and the diameters of the C4/5 and C5/6 foramens. The incidence of C5 palsy was 6.4% (9/141 cases). There were no significant differences between the 2 groups in sex, age, diagnosis, operation time, blood loss, level of spinal cord compression, level of T2 high-signal lesion, or new T2 high-signal lesions. The average diameter of the C4/5 foramen was 1.99 mm in the PG and 2.76 mm in the NPG (P<0.005). In contrast, the average diameter of the C5/6 foramen was 2.35 mm in PG and 2.50 mm in the NPG. There was a significant difference in the diameter of the C4/5 foramen between the PG and the NPG. The results suggest that the main etiology of C5 palsy is impairment of the C5 nerve root induced by preexisting C4/5 foraminal stenosis.

Chronological change of expanded lamina after cervical bilateral open door laminoplasty

Chronological change of expanded lamina after cervical bilateral open door laminoplasty

Clinical evaluation of guiding apparatus assisted individual posterior cervical pedicle screw fixation

Objective To evaluate the clinical effects of guiding apparatus assisted individual posterior cervical pedicle screw fixation technique. Methods The study enrolled 24 patients treated with posterior cervical decompressive single open-door laminoplasty and transpedicular screw-rod fixation from January 2008 to December 2010.The point of screw penetration and screw path direction were confirmed by measuring the transverse nail angle (TNA) and sagittal nail angle (SNA) of nail channel on the pre-operative CT plain scan of cervical pedicle and sagittal two-dimensional imaging of transpedicular axis.According to the results of CT measurement,individual cervical pedicle screw was implanted with the assistance of self-made guiding apparatus and then fixed after decompression.Transverse screw angle ( TSA ) and sagittal screw angle ( SSA ) were determined on the CT scan of cervical pedicle and sagittal two-dimensional imaging of transpedicular axis one week postoperatively in order to analyze the accuracy of placement of pedicle screws.Periodical anteroposterior and lateral X-ray radiographs of cervical vertebra were taken postoperatively to detect the stabilization of internal fixation. Results A total of 223 pedicle screws were inserted successfully into the C3 ～ C7,of which 220 crews were inserted accurately but three had slight inclination according to the postoperative CT,with placement accuracy of 98.7％.The comparison between inclination angle of inserted screws and that of preoperative transpedicular axis showed insignificant statistical difference ( P ＞ 0.05 ).All the patients were followed up for 6-34 months ( mean,18.5 months),which showed no neurovascular complications related to screws perforation out of pedicle cortex or no screw loosening,prolapse or breakage. Conclusion Posterior cervical pedicle screw insertionperformed according to the individual CT measurement is easy and safe and has a high accuracy rate under the assistance of self-made guiding apparatus. Key words: Cervical vertebrae; Fracture fixation, internal; Guiding apparatus

Open-Door Cervical Laminoplasty with Preservation of Posterior Structures

Objective To demonstrate that preservation of all posterior structures during open-door laminoplasty (ODL) is associated with a significant preservation of motion. Methods Fifteen patients underwent cervical ODL by one surgeon for treatment of cervical spondylotic myelopathy. An open-door technique was employed, and the laminae on the open side were reconstructed using miniplates with allograft strut bone graft. All spinous processes and interspinous and supraspinous ligaments were preserved within the operative levels and between supra- and subjacent levels in all patients. Postoperative radiographs were obtained 1.5, 3, 6, and 12 months. Computed tomography scans were obtained at 12 months. Results There were no significant intraoperative or perioperative complications. Postoperatively, the neutral angle was 6.8 ± 11.5 degrees (95% confidence interval: 0.5 to 13.1), representing a loss of lordosis of 3 degrees (not significant). The difference between the preoperative and postoperative arc range of motion was 5.96 ± 11.9 degrees (confidence interval: −0.62 to 12.5). The average percent loss of motion was 3.5% ± (0.1 to 6.9%). Four patients had an increased range of motion postoperatively. Conclusion Open-door laminoplasty with preservation of all posterior structures provides greater preservation of motion than has been previously described.

“Spring-back” closure associated with open-door cervical laminoplasty

Spring-back complication after open-door laminoplasty as described by Hirabayashi is a well-known risk, but its definition, incidence, and associated neurologic outcome remain unclear. To investigate the incidence and the neurologic consequence of spring-back closure after open-door laminoplasty. A retrospective radiographic and clinical review. Lateral cervical spine X-rays were evaluated. Anteroposterior diameters (APD) of the vertebral canal of C3-C7 were measured. Spring-back was defined as loss of APD on follow-up in comparison to immediate postoperative canal expansion. The loss of the end-on lamina silhouette with consequent reappearance of the lateral profile of the spinous processes was also assessed to verify the presence of spring-back. Spring-back closure was classified based on whether the collapse was total or partial, and whether all the operated levels or only a subset had collapsed (ie, complete vs. partial closure, segmental closure vs. total-construct closure). Neurologic status was documented using the Japanese Orthopaedic Association (JOA) score. Thirty consecutive patients who underwent open-door laminoplasty from 1995 to 2005 at a single institution with a minimum follow-up of 2 years were assessed. They were all operated on using the classic Hirabayashi technique. Radiographic outcomes were assessed independently by two individuals. Sixteen men and 14 women with an average follow-up of 5 years (range, 2-12 years) were included. Of these patients, 24 had cervical spondylotic myelopathy and six had ossification of the posterior longitudinal ligament. Spring-back closure was found in three patients (10%) and 7 of 117 laminae (6%) within 6 months of the operation, which was further confirmed by computed tomography and magnetic resonance imaging. All spring-back closures were partial segmental closures. Gender and age were not significant factors related to spring back (p>.05). The mean JOA score on follow-up was 12.5, with a recovery rate of 40%. All patients with spring back and available JOA data exhibited postoperative neurologic deterioration. Of the three patients with spring back, two patients underwent revision surgery, whereas one declined. Spring-back closure occurred in 10% of our patients at or before 6 months after surgery. The incidence of spring-back by level (ie, 117 laminae) was 6%, mainly occurring at the lower cervical spine. All spring-back closures were partial segmental closures, most commonly involving C5 and C6. Postoperative neurologic deficit was associated with spring-back closure; therefore, surgeons should adopt preemptive surgical measures to prevent the occurrence of such a complication.

Bilateral open-door expansive laminoplasty using unilateral posterior midline approach with preservation of posterior supporting elements for management of cervical myelopathy and radiculomyelopathy—analysis of clinical and radiological outcome and surgical technique

The purpose of this study was to evaluate bilateral open-door cervical laminoplasty for management of cervical canal stenosis secondary to multisegmental cervical spondylosis and ossified posterior longitudinal ligament. The importance of unilateral posterior approach with preservation of posterior supporting element is emphasized. Thirty-four patients had expansive laminoplasty. Posterior tension band consisting of nuchal ligaments and supraspinous and interspinous ligaments was secured. Paraspinal deep extensor muscles attached to one side of spinous process were also preserved. Hydroxyapatite-collagen spacers were positioned between split laminae in midline and secured with Ethibond. All patients had features of myelopathy with weakness, hypertonia, clonus, and hyperreflexia in both upper and lower limbs. Bladder and bowel involvement was seen in 11.7% and sexual dysfunction in 5.8%. Preoperative dynamic study of cervical spine, MRI, and/or CT were done in all patients and compared with postoperative studies to see the efficacy of the surgical procedure. Preoperative and postoperative neurosurgical cervical spine scale was used to compare results in relation to age, sex, duration of symptoms, neurosurgical cervical spine score, bladder, bowel, and sexual abnormalities. Elderly patients, lower neurosurgical score, signs and symptoms of more than 2years, and bladder, bowel, and sexual dysfunction had poorer outcome. Complications were few. All patients had adequate diameter of spinal canal postoperatively. Cervical alignment and range of motion of segment subjected to laminoplasty were preserved satisfactorily in follow-up. Bilateral open-door expansive laminoplasty using unilateral posterior midline approach provides preservation of posterior supporting tension band and excellent reconstruction of spinal canal. This technique also does not compromise contralateral paraspinal muscles attached to spinous process.

A modified unilateral open-door miniscrew-plate fixation:a biomechanical study

Objective To evaluate the biomechanical performance of a modified miniscrew-plate fixation in the unilateral open-door cervical laminoplasty.Methods Eight specimens of cervical spine (C3-C7) were made from intact adult cadavers.After randomization into 2 groups, with 4 specimens and 20 vertebral segments in each group, the unilateral open-door cervical laminoplasty was performed in each cervical vertebra in both groups.In group A the modified miniscrew-plates were used while in group B the traditional miniscrew-plates were implanted.A MTS880 machine was used to test the maximal load of the reclosed open-door miniscrew-plate at each cervical vertebra, and the maximal load and energy of the completely closed open-door miniscrew-plate.Results In the reclosing process, the mean maximal load was 873.61 ±154.40 N in group A and 297.17 ± 133.41 N in group B.In the complete closing state, the mean maximal load was 812.98 ± 141.79 N in group A and 145.77 ±59.21 N in group B; the mean energy was 5.95 ±0.83 J in group A and 1.65 ± 0.70 J in group B.There were significant differences between the 2 groups ( P ＜ 0.05 ) .Conclusion The modified miniscrew-plate can have better biomechanical performance than the traditional miniscrew-plate in simulated unilateral open-door cervical laminoplasty. Key words: Bone nails; Bone plates; Cervicoplasty; Biomechanics

The surgical care on the single cervical open-door laminoplasty with Centerpiece plate fixation

Objective To summarize the C3～7 the single cervical open-door laminoplasty with Centerpiece plate ( posterior cervical laminoplasty plate and screw fixation system) internal fixation surgery and nursing characteristics. Methods The surgeries in our hospital from August 2009 to January 2010 was investigate, which were 19 cases of cervical stenosis with posterior C3～7 single cervical open-door laminoplasty and Centerpiece plate fixation. The focused process was discussed, such as preoperative dynamic systems preparation, surgical position, the frame of the placement and intraoperative open the door and plate fixation device. Results 19 cases of posterior C3～7 single cervical open-door laminoplasty and Centerpiece plate fixation surgeries were uneventful and none of the reason for body position and power systems affected the surgical process. Operative time was 95～130 minutes, with an average time of 105 minutes; intraoperative blood loss was 290 ml; intraoperative C-arm X-ray confirmed Centerpiece plate in a good position. However, 1 patient appeared cerebral fluid leakage after operation and 7 patients appeared mild pain in the shoulder and neck accompanied by stiffness symptoms. There were no spinal cord injuries and complications such as hematoma. After 1 to 6 months follow-up there were no screw fixation instability, loosening, plate shift, and lamina phenomena occurred and the neurological function in patients recovered well. Conclusions The single cervical open-door cervical laminoplasty with Centerpiece plate technique is the better treatment of cervical stenosis as a surgical method. Mastering the use of Mayfield head frame, displaying good posture, getting a good knowledge of surgical procedures, preparing and using well the power system contribute to the operation completed successfully. Key words: Cervical spinal canal stenosis; Single open-door laminoplasty; Centerpiece plate; Surgical care

Short-term clinical outcome of modified expansive open-door cervical laminoplasty preserving posterior extensor musculature inserted into C2 and C7 spinous process

To assess the effect of modified cervical expansive open-door laminoplasty preserving the posterior extensor musculature inserted into the C2 and C7 spinous process upon maintaining the cervical lordotic alignment and axial syndrome and to determine whether preserving the posterior extensor musculature inserted into C2 and C7 spinous process can reduce the complications. Twenty-eight patients undergoing modified cervical expansive open-door laminoplasty preserving the posterior extensor musculature inserted into the C2 and C7 spinous process and 21 patients undergoing conventional C3-C7 cervical expansive open-door laminoplasty were investigated in pre-operative, post-operative and 3-month follow-up. The investigators assessed the effects of two different cervical laminoplasty types in the recovery rate of JOA score, the changes of Cobb angle and Ishihara's index, axial syndrome, operating duration and intra-operative blood loss, analyzed the results in SPSS and tried to find the difference in two operative types. There were the same results in the recovery rate of JOA score and intra-operative blood loss in modified expansive open-door cervical laminoplasty group and the conventional C3-C7 cervical expansive open-door laminoplasty group. The smaller changes of Cobb angle and Ishihara's index in the follow-up of modified laminoplasty group were found. The modified laminoplasty group had fewer patients suffering the axial syndrome in follow-up. The operating duration was shorter in the modified laminoplasty group. Preventing muscle injuries in cervical laminoplasty can reduce the incidence of complications. The modified expansive open-door cervical laminoplasty preserving the posterior extensor musculature inserted into C2 and C7 spinous process can protect cervical posterior extensor musculature. This is helpful to maintain the cervical lordotic alignment and reduce the incidence of post-operative axial syndrome.

New Titanium Spacer for Cervical Laminoplasty: Initial Clinical Experience -Technical Note-

Many commercially available hydroxyapatite (HA) spacers for cervical laminoplasty have been introduced but have disadvantages such as lack of plasticity, easy cracking, and occasional difficulty in fixation by sutures. Here we present the short-term results of a newly designed titanium spacer (Laminoplasty Basket) in open-door cervical laminoplasty, and evaluated clinically and radiologically. The titanium box-shaped spacer with two arms for fixation was easily inserted and fixed into the laminoplasty space with 4-mm or 5-mm length screws after the posterior cervical arch was repositioned for the canal expansion. Twenty-one patients with cervical myelopathy due to spondylosis or ossification of the longitudinal ligament or developmental narrow canal observed for more than 6 months postoperatively were enrolled in this study. The neurological condition of these patients improved from 9.4 points on the Japanese Orthopaedic Association scale preoperatively to 13.5 points at 6 months after surgery. Postoperative radiological evaluation showed no laminar closure or implant failure and cervical spine curvature was maintained. These results seemed to have no significant difference compared with those using HA spacers. This titanium spacer is a potential substitute for conventional HA or other similar devices in cervical laminoplasty.