Expansive laminoplasty for myelopathy in ossification of the longitudinal ligament

Exoscopic Minimally Invasive Open-Door Laminoplasty for Cervical Myelopathy: A Technical Note and Preliminary Analysis of Clinical Outcomes during the Acute Postoperative Period

Background/Objectives: Expansive open-door laminoplasty results in favorable clinical outcomes for cervical myelopathy. However, some postoperative complications associated with surgical invasiveness, such as axial neck pain and kyphosis, have not been resolved. The use of an exoscope, which is a recently introduced novel magnification tool, allows for traditional open-door laminoplasty with minimal invasiveness. Therefore, we propose the use of exoscopic minimally invasive open-door laminoplasty (exLAP) and present its clinical outcomes during the acute postoperative period. Methods: A total of 28 patients who underwent open-door laminoplasty at C3-C6 were reviewed. Of these patients, 17 underwent exLAP (group M) and 11 underwent conventional Hirabayashi open-door laminoplasty (group H). Outcomes were evaluated using numerical rating scale (NRS) scores for neck pain and the frequency of oral analgesic use from postoperative day 1 to 7. Results: The NRS score for neck pain was significantly lower for patients in group M than for those in group H. Conclusions: ExLAP is a novel, practical, and minimally invasive surgical technique that may alleviate the postoperative axial pain of patients with cervical myelopathy.

Management of C5 Palsy After Anterior Cervical Decompression Using Oberlin Nerve Transfer: A Case Report

C5 palsy is a potential complication of cervical decompression surgery from which many patients do not recover or partially recover function. We present the case of a 48-year-old patient who developed elbow flexion paralysis after anterior decompression surgery with fusion of the C5-C7 levels. Muscle function was not spontaneously restored until eight months after surgery. In this case, we performed an Oberlin procedure to restore the function of the arm. Muscle strength (5/5) and volume were obtained 13 months after surgery. A reasonable waiting period is required after C5 palsy in case spontaneous recovery occurs. Treatment decision should be based on the patient's symptoms. Nerve transfers have been shown to be effective when performed after six months, especially in Oberlin transfer.

Posterior Hybrid Technique for the Treatment of Traumatic Cervical Spinal Cord Injury with High Signal Intensity on T2WI

Objective

To evaluate the efficacy of the posterior hybrid technique (PHT) for the treatment of traumatic cervical spinal cord injury without vertebral fracture or dislocation with high signal intensity on T2WI (CSCIH).

Methods

A comparative analysis of clinical efficacy between CSCIH patients who underwent anterior decompression and fusion (ADF) surgery and those who underwent PHT surgery was retrospectively conducted. Demographic characteristics, cervical range of motion (CRM), cross-sectional area of spinal cord (CSASC), spinal canal area residual rate (SCARR), high signal intensity ratio (HSIR), Cervical Japanese Orthopedic Association (CJOA) score, and neck disability index (NDI) were assessed.

Results

Forty-three CSCIH cases with PHT and 46 CSCIH cases with ADF were collected from January 2013 to January 2017. The CRM in patients with PHT was superior to that in patients with ADF at the final follow-up (64.21 ± 18.46° vs. 48.71 ± 19.34°, p = 0.0002). The SCARR also showed greater improvements in the PHT group than in the ADF group (final follow-up: 93.54 ± 11.09% vs. 88.13 ± 10.84%, p = 0.022). Both groups indicated significant improvements in the CSASC and HSIR (p < 0.05); however, no significant differences were observed between the two groups. All patients showed improvements in the CJOA score and the NDI after surgery (p < 0.05). At the 6-month follow-up, the ADF group had better NDI scores than the PHT group (31.17 ± 10.42 vs. 36.78 ± 9.65, p = 0.010), whereas the PHT group exhibited better improvements than the ADF group at the final follow-up (66.86 ± 9.28% vs. 57.67 ± 10.22%, p < 0.0001).

Conclusion

The PHT was as effective as ADF in the treatment of CSCIH, whereas the PHT was superior in the improvement of patients' health-related quality of life and in CRM preservation during the long-term follow-up.

Combined cervical laminoplasty and foraminotomy for coexistence of cervical myelopathy and unilateral radiculopathy: case series and preliminary results

BACKGROUND

The clinical outcomes and radiographic changes of a one-stage procedure combining cervical laminoplasty and unilateral cervical foraminotomy for patients with coexisting cervical myelopathy and unilateral radiculopathy were evaluated.

METHODS

Seven patients (two females and five males) with coexisting cervical myelopathy and unilateral cervical radiculopathy were included in this study. The mean age was 58.4 years (range 45-77 years). Cervical laminoplasty and unilateral cervical foraminotomy were performed on the recruited patients in a single stage. The quantitative clinical changes between the preoperative and 6-month postoperative assessment were analyzed using the Japanese Orthopedic Association (JOA) score, the JOA Cervical Myelopathy Evaluation Questionnaire (JOA-CMEQ), visual analog scale (VAS), and Neck Disability Index (NDI). Moreover, the preoperative and 6-month postoperative radiographic changes were assessed using the C2-7 angle and range of motion (ROM) between flexion and extension angle.

RESULTS

There were significant differences in QOL in the JOA-CMEQ between the groups. Furthermore, the postoperative VAS values in the arms and hands generally improved, although not significantly, between the groups.

CONCLUSIONS

The aforementioned surgical procedure may be safe and efficient for patients with coexisting cervical myelopathy and radiculopathy.

Technical Nuances of Cervical Laminoplasty: Supplemental Manuscript to Operative Video

STUDY DESIGN

Operative video and supplemental manuscript.

OBJECTIVE

The technical nuances of open-door laminoplasty are described. Potential complications of open-door laminoplasty and strategies for their minimization are discussed.

SUMMARY OF BACKGROUND DATA

Cervical laminoplasty may be indicated in patients with cervical myelopathy due to cervical stenosis in the setting of spondylosis, ossification of the posterior longitudinal ligament, congenital stenosis, and traumatic central cord syndrome.

METHODS

A video illustrates the nuances of the surgical technique for cervical laminoplasty.

RESULTS

Myelopathic patients with preserved lordotic sagittal profile, central stenosis involving several levels, and minimal to no axial neck pain are ideal candidates for laminoplasty.

CONCLUSIONS

Cervical laminoplasty provides more stability compared with laminectomy alone and a better range of motion compared with laminectomy with posterior spinal fusion. Understanding the nuances of laminoplasty may help surgeons to avoid complications.

The cervical sagittal curvature change in patients with or without PCSM after laminoplasty

Objective

After laminoplasty, the cervical sagittal curvature of some patients tend to be lordotic, this phenomenon cannot be explained by the theory of laminoplasty, and the reason remains unknown. We explored the possible role played by pinching cervical spondylotic myelopathy (PCSM) in the cervical sagittal curvature change in patients after laminoplasty.

Methods

From April 2017 to May 2019, we studied 122 patients undergoing laminoplasty with cervical spondylotic myelopathy (CSM). All patients were divided into Group A (anterior compression only, without PCSM) and Group B (both anterior and posterior compression, with PCSM). The visual analogue scale (VAS) was used to measure pain, and modified Japanese Orthopedic Association (mJOA) score was derived. The cervical global angle (CGA) and the range of cervical motion (ROM) were compared. The clinical and imaging results were compared between Group A and Group B.

Results

After laminoplasty, both the mean VAS and mJOA scores improved significantly in Group A and Group B, the mJOA recovery rate of Group B was better than that of Group A (P < 0.05). The mean CGA and ROM decreased in Group A, but increased in Group B. MRI revealed that the ligamentum flavum of Group A was significantly thinner than that of Group B (P < 0.05).

Conclusions

Because of the hypertrophic and folded ligamentum flavum compressing the dorsal spinal cord, patients with PCSM may maintain a compulsive kyphotic posture. After laminoplasty, the cervical sagittal curvature of these patients tend to be lordotic due to the release of dorsal spinal cord compression.

Optimizing the Application of Surgery for Degenerative Cervical Myelopathy [AO Spine RECODE-DCM Research Priority Number 10]

STUDY DESIGN

Literature Review (Narrative).

OBJECTIVE

To introduce the number 10 research priority for Degenerative Cervical Myelopathy: Individualizing Surgery.

METHODS

This article summarizes the current recommendations and indications for surgery, including how known prognostic factors such as injury time, age, disease severity, and associated comorbidities impact surgical outcome. It also considers key areas of uncertainty that should be the focus of future research.

RESULTS

While a small proportion of conservatively managed patients may remain stable, the majority will deteriorate over time. To date, surgical decompression is the mainstay of treatment, able to halt disease progression and improve neurologic function and quality of life for most patients. Whilst this recognition has led to recommendations on when to offer surgery, there remain many uncertainties including the type of surgery, or timing in milder and/or asymptomatic cases. Their clarification has the potential to transform outcomes, by ensuring surgery offers each individual its maximum benefit.

CONCLUSION

Developing the evidence to better guide surgical decision-making at the individual patient level is a research priority for Degenerative Cervical Myelopathy.

One Hundred Top Cited Articles in Cervical Myelopathy: A Bibliographic Analysis

STUDY DESIGN

A bibliometric review of the literature.

OBJECTIVES

The aim of this study was to identify the most highly cited articles relating to cervical myelopathy and to analyze the most influential articles.

SUMMARY OF BACKGROUND DATA

Over the past several decades, a lot of research has been conducted regarding the subject of cervical myelopathy. Although there are a large number of articles on this topic, to our knowledge, this is the first bibliometric analysis.

METHODS

A selection of search terms and keywords were inputted into the "Dimensions" database and the most highly cited articles in cervical myelopathy were selected from high impact factor journals. The top 100 articles were analyzed for year of publication, authorship, publishing journals, institution and country of origin, subject matter, article type, and level of evidence.

RESULTS

The 100 most cited articles in the topic of cervical myelopathy were published from 1956 to 2015. These articles, their corresponding authors, and number of citations are shown in Table 1. The number of citations ranged from 121 times for the 100th article to 541 times for the top article in a total of 20 journals. The most common topic was operative technique, whereas the journals which contributed the most articles were the Spine journal and the Journal of Neurosurgery.

CONCLUSION

Our study provided an extensive list of the most historically significant articles regarding cervical myelopathy, acknowledging the key contributions made to the advancement of this field.Level of Evidence: 5.

Comparison of Surgical Outcomes After Open- and Double-Door Laminoplasties for Patients with Cervical Ossification of the Posterior Longitudinal Ligament: A Prospective Multicenter Study

STUDY DESIGN

A prospective multicenter study.

OBJECTIVE

To evaluate and compare the surgical outcomes after open-door (OD) and double-door (DD) laminoplasties in subjects with cervical ossification of the posterior longitudinal ligament (OPLL).

SUMMARY OF BACKGROUND DATA

Although previous studies compared clinical results after OD and DD laminoplasties, they were performed at a single institution with a relatively small sample size targeting mixed pathologies, including cervical spondylotic myelopathy.

METHODS

This study was performed by the Japanese Multicenter Research Organization for Ossification of the Spinal Ligament. A total of 478 patients with myelopathy caused by cervical OPLL from 28 institutions were prospectively registered from 2014 to 2017 and followed up for 2 years. Of these, 41 and 164 patients received OD and DD laminoplasties, respectively. Demographic information, medical history, and imaging findings were collected. Clinical outcomes were assessed using the cervical Japanese Orthopaedic Association, Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire, and visual analog scale scores.

RESULTS

Age, sex, symptom duration, and comorbidities were not significantly different between the groups. Segmental ossification was the most frequent in both the groups. No significant differences in K-line type, canal occupying ratio, C2 to C7 angles, and range of motion were found. Both the procedures reduced the cervical range of motion postoperatively. A comparable frequency of perioperative complications was observed between the groups. The cervical Japanese Orthopaedic Association scores showed a similar improvement at 2 years postopera- tively. The reduction in visual analog scale score for neck pain was favorable in the OD group (P = 0.02), while other pain assessments did not show any significant differences between the groups. The functional outcomes assessed using the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire presented equivalent effective rates.

CONCLUSION

The results demonstrated almost comparable surgical outcomes between OD and DD laminoplasties. Lamino- plasty is a valuable technique as a therapeutic option for cervical OPLL.Level of Evidence: 2.

Association Between C5 Palsy and the Anterior Decompression Procedures, Corpectomy and Discectomy

STUDY DESIGN

This is a retrospective study.

OBJECTIVE

The aim was to evaluate the influence of various decompression procedures on the incidence of C5 palsy (C5P).

SUMMARY OF BACKGROUND DATA

C5P is a well-known but unsolved complication of cervical spine surgery. Among anterior cervical decompressive procedures, both corpectomy and discectomy are important surgical methods, whose effects on the incidence of C5P are unknown.

METHODS

We retrospectively analyzed 818 patients (529 men; mean age: 59.2±11.6 y) who underwent anterior cervical decompression and fusion. The surgical choice to use corpectomy, discectomy, or hybrid decompression was based on standard treatment strategies depending on local compressive pathology and presenting clinical symptoms. We introduced an original "decompression combination score" as a means of quantifying the effects of the procedures on the development of C5P. The scores were based on the relative severity of various risk factors associated with the eventual development of C5P and were assigned as follows: C4 corpectomy, 1 point; C5 corpectomy, 1 point; C3 corpectomy successive to C4 corpectomy, 0.5 point; C6 or C7 corpectomy successive to C5 corpectomy, 0.5 point; C4/5 discectomy, 0.5 point; discectomy at another segment, 0 point. Each patient's decompression combination score was then comprised of the sum of these points.

RESULTS

C5P occurred in 55 (47 men, mean age: 65.7±8.7 y) of the 818 (6.7%) patients. A larger number of operated disc segments was significantly associated with C5P. Higher decompression combination score was significantly associated with C5P. Multivariate analysis revealed that male sex, higher decompression combination score, and older age were significant risk factors.

CONCLUSIONS

Corpectomy increased the incidence of C5P, while discectomy decreased the risk. The lower incidence of postoperative C5P after discectomy may be because of minimizing tethering effect to the C5 nerve root. As a preventive measure against C5P, corpectomy should be avoided, while discectomy is recommended as much as possible.

LEVEL OF EVIDENCE

Levels of Evidence: Step IV-Oxford Center for Evidence-Based Medicine 2011.

Laminoplasty with selective fusion at unstable segment versus laminectomy with fusion for multilevel cervical myelopathy: a case-control study

Background

Segmental cervical instability is a risk factor for the progression of osteophytic bone spurs and development of myelopathy, and is treated as a relative contraindication of cervical laminoplasty. The aim of this study was to compare laminoplasty with selective fixation (LPSF) versus laminectomy with fusion (LCF) in patients with multilevel cervical myelopathy accompanied by segmental instability.

Methods

A case-control study was conducted by reviewing data from 63 patients who underwent LPSF (n = 30) or LCF (n = 33). Cervical alignment, range of motion (ROM), neurologic status and axial symptom severity pre-operation, 3-days after operation, and at the final follow-up (minimum 24 months) were measured and compared between groups.

Results

Postoperation, patients in the LPSF group lost 31.1 ± 17.3 % of cervical lordosis and 43.2 ± 10.9 % cervical ROM while patients in the LCF group lost 5.7 ± 8.2 % and 67.9 ± 15.5 %, respectively. Both LPSF and LCF groups significantly improved neurologic status and axial symptom severity at the final follow-up with similar between-group results(P > 0.05). Blood loss, operation time, hospital stay, and medical cost in the LPSF group were significantly less than in the LCF group(P < 0.05).

Conclusions

In 2 years of clinical observation, LPSF was effective in maintaining the stability of the cervical spine with less sacrifice of mobility and surgical trauma for multilevel myelopathy with segmental instability compared to LCF.

Spinal Cord Drift Following Laminoplasty Versus Laminectomy and Fusion for Cervical Spondylotic Myelopathy

BACKGROUND

Cervical laminoplasty and laminectomy and fusion (LF) are posterior-based surgical techniques for the surgical treatment of cervical spondylotic myelopathy (CSM). Interestingly, the comparative amount of spinal cord drift obtained from these procedures has not been extensively described. The purpose of this study is to compare spinal cord drift between cervical laminoplasty and LF in patients with CSM.

METHODS

The laminoplasty group consisted of 22 patients, and the LF group consisted of 44 patients. Preoperative and postoperative alignment was measured using the Cobb angle (C2-C7). Spinal cord position was measured on axial T2-magnetic resonance imaging of the cervical spine preoperatively and postoperatively. Spinal cord drift was quantified by subtracting preoperative values from postoperative values. Functional improvement was assessed using the modified Japanese Orthopaedic Association (mJOA) score.

RESULTS

Mean spinal cord drift was higher following LF compared to laminoplasty (2.70 vs 1.71 mm, P < .01). Using logistic regression analysis, there was no correlation between sagittal alignment and spinal cord drift. Both groups showed an improvement in mJOA scores postoperatively compared to their preoperative values (laminoplasty, +2.0, P = .012; LF, +2.4, P < .01). However, there was no difference in mJOA score improvement postoperatively between both groups (P = .482).

CONCLUSIONS

This study demonstrates that patients who had LF for CSM achieved more spinal cord drift postoperatively compared to those who had laminoplasty. However, the increased drift did not translate into superior functional outcome as measured by the mJOA score.

LEVEL OF EVIDENCE

3.

CLINICAL RELEVANCE

Spinal cord drift following LF may differ from laminoplasty in patients undergoing surgery for CSM. This finding should be considered when assessing CSM patients for surgical intervention.

Person-in-the-barrel syndrome following cervical spine surgery: illustrative case

BACKGROUND

Person-in-the-barrel syndrome is characterized by bilateral brachial diplegia, intact cranial nerves, and preserved lower-extremity strength. Most cases are due to bilateral supratentorial brain lesions at the border zone of the anterior and middle cerebral artery vascular territories. This condition has been observed with spinal pathology, primarily involving vascular dissection and thromboembolism.

OBSERVATIONS

The authors’ case is the first in the literature to highlight person-in-the-barrel syndrome immediately following cervical spine surgery. Weakness of the deltoids, biceps, infraspinatus, and brachioradialis was observed bilaterally postoperatively. Electromyograph (EMG)-nerve conduction velocity (NCV) studies revealed a cervical radiculopathy involving C5 and C6 bilaterally with denervation of the deltoids, biceps, and brachioradialis. Within 8 months of cervical spine surgery, the patient regained improvement of the bilateral brachial diplegia.

LESSONS

EMG/NCV studies play a valuable role in detecting cervical radiculopathy after cervical spine surgery in patients with bilateral brachial diplegia. The authors postulate that this condition may have occurred following neck hyperextension during cervical cage placement, increasing the foraminal stenosis at C4–5 and C5–6 and worsening the C5 and C6 radiculopathy. Spinal surgeons should be cognizant of person-in-the-barrel syndrome that may ensue following cervical spine surgery and promptly identify and treat this condition to offer the best prognosis for a favorable patient outcome.

Anatomical study of cervical intervertebral foramen in patients with cervical spondylotic radiculopathy

PURPOSE

To determine the underlying anatomical characteristics in patients with cervical spondylotic radiculopathy (CSR) by comparing those of surgically treated CSR patients with those of healthy subjects.

METHODS

Computed tomography (CT) scans of the cervical spine in 42 patients who underwent decompression surgery for CSR were investigated. As a control group, 42 age- and sex-matched healthy subjects were randomly selected from the 1272 subjects who underwent CT examinations of the entire spine as their routine medical check-up. Image measurements included C2-7 sagittal Cobb angle, spinal canal diameters, and angles of the nerve root groove at each level from C3 to C7, and the size of the intervertebral foramen and the size of osteophytes at each level from C3/4 to C7/T1. As for the frequency of osteophytes at the surgical level, we compared the operated and nonoperated intervertebral foramina among the CSR patients, and all other parameters were compared with the corresponding segments in the control group.

RESULTS

Forty-eight intervertebral segments were surgically treated in the CSR group. There was a higher incidence of osteophytes in the operated foramen (70.8%) than in the nonoperated foramen (28.2%, p < 0.01) in the patients with CSR. The anteroposterior diameter (width) of the foramen was significantly smaller at all levels in the CSR patients, whereas the height of the foramen did not significantly differ between the two groups.

CONCLUSION

It can be speculated that the width of the intervertebral foramen (developmental factor) and the formation of osteophytes (spondylotic factor) were related to the onset of the CSR.

The importance of preoperative T1 slope for determining proper postoperative C2-7 Cobb's angle in patients undergoing cervical reconstruction

BACKGROUND

This study aimed to explore the relationship among different cervical sagittal parameters in asymptomatic volunteers and the correlation between surgical efficacy and difference of presumed and actual postoperative C2-7 Cobbs's angle (C2-7COBB), which was calculated based on preoperative T1 slope (T1S) in patients undergoing cervical reconstruction.

METHODS

In total, 158 inpatients with cervical spondylosis and 274 asymptomatic volunteers were retrospectively reviewed. Cervical sagittal parameters, such as C2-7COBB, T1S, thoracic inlet angle (TIA), and neck tilt (NT), were compared. Then, the correlation among these parameters was analyzed in asymptomatic volunteers, and a regression equation between T1S and C2-7COBB was established and used to analyze the correlation among the Japanese Orthopaedic Association (JOA) score improvement, the sagittal parameters, and the difference between presumed and actual postoperative C2-7COBB in patients after cervical reconstruction.

RESULTS

The mean T1S, C2-7COBB, and TIA were significantly decreased in patients (P < 0.01). T1S and NT had a strong correlation with TIA (P < 0.01). T1S demonstrated a moderate correlation with C2-7COBB in asymptomatic volunteers (r = 0.569, P < 0.01). A regression equation had been established as C2-7COBB = 0.742 × T1S - 0.866. The mean C2-7COBB and JOA score improved significantly (P < 0.05) postoperatively. Moreover, the JOA improvement rate showed a significant negative correlation with the difference in the presumed and actual postoperative C2-7COBB (r = - 0.696, P < 0.01).

CONCLUSION

Our study successfully established a regression equation for calculating postsurgical C2-7COBB based on the correlation between T1S and C2-7COBB in asymptomatic volunteers. The regression equation could be used for guiding surgeons to accomplish an ideal postsurgical C2-7COBB for patients with cervical spondylosis.

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

BACKGROUND

Postoperative 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.

PURPOSE

To investigate the anatomical mechanism of postoperative C5 palsy after cervical expansive open-door laminoplasty.

STUDY DESIGN

A dissection-based study of eight embalmed human cadavers.

METHODS

The 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.

RESULTS

One 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.

CONCLUSION

Traction 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 SIGNIFICANCE

This 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.

The Severity of Cervical Disc Degeneration Does Not Impact 2-year Postoperative Outcomes in Patients With Cervical Spondylotic Myelopathy Who Underwent Laminoplasty

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The aim of this study was to evaluate the impact of cervical disc degeneration (CDD) severity on 2-year postoperative outcomes following laminoplasty.

SUMMARY OF BACKGROUND DATA

The impact of CDD on postoperative outcomes of cervical laminoplasty has not been well established.

METHODS

A total of 144 patients who underwent open-door laminoplasty for cervical spondylotic myelopathy (CSM) were enrolled. Six cervical discs were independently analyzed for degeneration severity using a previously reported grading system (grade 0: none, grade 3: severest). The relationship between the segmental range of motion (ROM) and the severity of CDD was evaluated. Subsequently, after dividing overall patients into mild and severe CDD groups by the average of CDD scores, the mixed-effect model was applied to assess 2-year postoperative outcomes, including physician-assessed myelopathy scores, patient-reported outcomes, and preoperative radiographic parameters. Finally, as additional analysis, the severe CDD group was further divided into two groups: group 1 included patients with a grade 3 CDD change in their most stenotic level and group 2 included the others. The 2-year postoperative myelopathy score was compared between groups 1 and 2.

RESULTS

The cervical segments with grade 3 CDD showed significantly smaller ROM compared with those with grade 0, 1, or 2 CDD (P < 0.01). There were no significant differences in postoperative improvements in myelopathy, pain, patient-reported physical and mental status, and radiographic parameters, except for quality of life (QOL) scores between CDD groups. A significant (P = 0.02) postoperative improvement in QOL scores was noted in the severe CDD group. In an additional analysis, myelopathy score at 2 years postoperatively was significantly higher in group 1 than group 2 (P = 0.041).

CONCLUSION

The severity of CDD did not negatively impact 2-year postoperative laminoplasty outcomes. The postulated reason is that the decreased segmental instability in the level with severe CDD may affect surgical outcomes positively.

LEVEL OF EVIDENCE

3.

Residual numbness of the upper extremity after cervical surgery in patients with cervical spondylotic myelopathy

OBJECTIVE

Although numbness is one of the chief complaints of patients with cervical spondylotic myelopathy (CSM), preoperative factors relating to residual numbness of the upper extremity (UE) and impact of the outcomes on cervical surgery are not well established. The authors hypothesized that severe preoperative UE numbness could be a risk factor for residual UE numbness after surgery and that the residual UE numbness could have a negative impact on postoperative outcomes. Therefore, this study aimed to identify the preoperative factors that are predictive of residual UE numbness after cervical surgery and demonstrate the effects of residual UE numbness on clinical scores and radiographic parameters.

METHODS

The study design was a retrospective cohort study. The authors analyzed data of 103 patients who underwent cervical laminoplasty from January 2012 to December 2014 and were followed up for more than 2 years postoperatively. The patients were divided into two groups: the severe residual-numbness group (postoperative visual analog scale [VAS] score for UE numbness > 40 mm) and the no/mild residual-numbness group (VAS score ≤ 40 mm). The outcome measures were VAS score, Japanese Orthopaedic Association scores for cervical myelopathy, physical and mental component summaries of the 36-Item Short-Form Health Survey (SF-36), radiographic film parameters (C2-7 sagittal vertical axis, range of motion, C2-7 lordotic angle, and C7 slope), and MRI findings (severity of cervical canal stenosis, snake-eye appearance, severity of foraminal stenosis). Following univariate analysis, which compared the preoperative factors between groups, the variables with p values < 0.1 were included in the multivariate linear regression analysis. Additionally, the changes in clinical scores and radiographic parameters after 2 years of surgery were compared using a mixed-effects model.

RESULTS

Among 103 patients, 42 (40.8%) had residual UE numbness. In the multivariate analysis, sex and preoperative UE pain were found to be independent variables correlating with residual UE numbness (p = 0.017 and 0.046, respectively). The severity of preoperative UE numbness did not relate to the residual UE numbness (p = 0.153). The improvement in neck pain VAS score and physical component summary of the SF-36 was significantly low in the severe residual-numbness group (p < 0.001 and 0.040, respectively).

CONCLUSIONS

Forty-one percent of the CSM patients experienced residual UE numbness for at least 2 years after cervical posterior decompression surgery. Female sex and preoperative severe UE pain were the predictive factors for residual UE numbness. The patients with residual UE numbness showed less improvement of neck pain and lower physical status compared to the patients without numbness.

Open-Door Laminoplasty Using Lateral Mass Anchoring Screws and Nonabsorbable Sutures in Patients with Multilevel Cervical Myelopathy

Backgroud

The purpose of this study was to evaluate the clinical usefulness of open-door laminoplasty using lateral mass anchoring screws and nonabsorbable sutures (ODLLM) for multilevel cervical myelopathy.

Methods

We retrospectively studied 30 patients who underwent ODLLM. Clinical evaluations were performed using a visual analog scale (VAS), Japanese Orthopaedic Association (JOA) score, and Neck Disability Index (NDI) preoperatively, at 1 year postoperatively, and at the last follow-up. Radiographic evaluation was done using cervical spine radiographs to measure changes in the lordotic angle and range of motion (ROM) preoperatively, at 1 year postoperatively, and at the last follow-up and computed tomography at 1 year postoperatively to measure the opening angle and anteroposterior diameter of the spinal canal.

Results

Significant improvement in VAS, JOA, and NDI was seen overall at 1 year after operation. However, there was no significant difference between 1 year after operation and the last follow-up. There were no significant changes in the lordotic angle and neck ROM. The mean opening angle of the opened lamina was measured as 39.04°. The mean anteroposterior diameter was significantly increased from 7.51 ± 1.79 mm before surgery to 13.98 ± 1.80 mm at 1 year of operation. Complications such as laminar reclosure and screw loosening were not observed in all cases.

Conclusions

The ODLLM was technically easy to perform and showed good results comparable to those of conventional techniques. It can be suggested that ODLLM is an appropriate treatment option for multilevel cervical myelopathy.

Improvement in Patient Mental Well-being After Surgery for Cervical Spondylotic Myelopathy

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The aim of this study was to investigate changes in mental well-being after surgery for cervical spondylotic myelopathy (CSM) and identify factors associated with improvement.

SUMMARY OF BACKGROUND DATA

Posterior cervical surgery with laminoplasty significantly improves myelopathy and physical function in patients with CSM. However, its impact on mental well-being is unclear.

METHODS

Patients who underwent laminoplasty for CSM and had >2 years of follow-up were reviewed (n = 111). The mental component summary (MCS) score was used as a measure of mental well-being. The trend in MCS score change was evaluated using the Jonckheere-Terpstra trend test. Preoperative clinical scores were compared between patients with improvements greater and less than the minimal clinically important difference (MCID). Significant variables were included in a multinomial logistic regression analysis and further validated in a receiver-operating characteristic (ROC) curve analysis. Additionally, the results were confirmed in a long-term observation cohort of patients followed up for >5 years (n = 46).

RESULTS

The improvement in the average MCS score (5.6) was greater than the MCID (4.0). The trend of improvement was sustained for 2 years (P = 0.002), but not for 5 years (P = 0.130). In terms of individual cases, 56 patients (50.5%) achieved MCS score improvement greater than the MCID. These patients showed significantly lower preoperative MCS scores than those without meaningful improvement (P < 0.001). The preoperative "social functioning (SF)" score was independently associated with MCS score improvement (P = 0.001). ROC curve analysis validated the ability of preoperative SF to predict MCS score improvement at 2 and 5 years postoperatively (area under the curve: 0.744, 0.893, respectively).

CONCLUSION

Half of the patients achieved meaningful improvement in mental well-being. A lower preoperative SF score was independently associated with improvement. These results may help identify patients who could experience an improvement in mental well-being after surgery and develop novel approaches to achieve further improvement.

LEVEL OF EVIDENCE

3.

Clinical Impact of Cervical Imbalance on Surgical Outcomes of Laminoplasty: A Propensity Score-Matching Analysis

STUDY DESIGN

This is a retrospective cohort study.

OBJECTIVE

The objective of this study was to identify the impact of preoperative cervical sagittal balance on the 2-year surgical outcomes of laminoplasty.

SUMMARY OF BACKGROUND DATA

The cervical imbalance is considered associated with poor health-related quality of life and poor outcomes for cervical deformity surgery. However, the influences of cervical imbalance on the clinical outcomes of laminoplasty for cervical spondylotic myelopathy (CSM) patients are unclear.

MATERIALS AND METHODS

A total of 277 consecutive CSM patients who underwent laminoplasty were analyzed. From the last consecutive 136 patients, matched control group [cervical sagittal vertical axis (cSVA)<40 mm, n=30] and matched imbalance group (≥40 mm, n=30) were selected based on their propensity score adjusted for age, sex, cervical alignment, and preoperative Japanese Orthopaedic Association (JOA) score. Change in clinical outcomes and radiographic parameters at 2 years postoperatively were compared between the 2 matched groups using mixed-effects model. For the validation of the primary results, factors that correlated with the recovery rate of JOA score of another 141 patients were analyzed using multiple linear regression analysis.

RESULTS

There was no significant interaction between the 2 matched groups in all clinical outcomes, including the severity of myelopathy, patient-oriented health-related quality of life score, physical and mental status, physical functions, and pain score. Regarding the radiographic evaluation, change in cSVA showed significant differences (P=0.038); cSVA was kept stable in the matched control group, whereas its value significantly decreased in the matched imbalance group. Multiple linear regression models demonstrated that preoperative cSVA is not significantly related to the recovery rate of JOA score at 2 years postoperatively (P=0.114).

CONCLUSIONS

Preoperative cervical imbalance did not significantly affect the 2-year surgical outcomes of laminoplasty. Furthermore, cervical imbalance improved after surgery. These results can suggest physicians consider laminoplasty as a treatment for CSM patients regardless of their cervical balance.

LEVEL OF EVIDENCE

Level III-treatment benefits: nonrandomized controlled cohort/follow-up study.

Does Ossification of the Posterior Longitudinal Ligament Progress After Fusion?

Starting in the 1960s, ossification of the posterior longitudinal ligament (OPLL) became more commonly diagnosed in Japan. The disease is characterized by a gradual increase in calcification of the posterior longitudinal ligament with the eventual sequelae of cervical canal stenosis and myelopathy. Surgical interventions to relieve stenosis and neurologic symptoms are performed to decompress the cervical canal. Studies demonstrate continued ossification of the OPLL in both nonsurgical and surgically treated patients. In this review, the authors evaluate the epidemiology, pathophysiology, and literature regarding disease progression in OPLL after cervical fusion.

Posterior Revision Surgery for Cervical Open-Door Laminoplasty Because of Poor Expansion of the Spinal Canal

OBJECTIVE

Few studies have addressed the causes of poor expansion of the spinal canal after open-door laminoplasty (ODL) that require revision surgery. The aim of this study is to identify the reasons of poor expansion of the spinal canal after ODL and to discuss the surgical methods and clinical outcomes of the posterior revision surgery.

METHODS

All patients who underwent posterior revision surgery because of poor expansion of the spinal canal after ODL were retrospectively reviewed at our spine center. Clinical data, radiologic findings, method of surgical revision, interval between surgeries, Japanese Orthopaedic Association (JOA) score, and complications were analyzed.

RESULTS

We identified 16 patients that underwent posterior revision surgery because of poor expansion of the spinal canal after ODL. The main causes of poor expansion of the spinal canal included inadequate expansion degree of the spinal canal (75%, 12/16) and improper expansion range of the spinal canal (25%, 4/16). Revision surgery was performed with posterior ODL, laminectomy and fusion (LCF), or laminectomy of responsible lamina. The interval between the initial procedure and revision surgery was 72.2 months (range, 0.5-168 months). The mean JOA score was restored from 10.6 (range, 8-13) to 14.3 (range, 13-17) after the revision surgery.

CONCLUSIONS

The main causes of poor expansion of the spinal canal after ODL were inadequate expansion degree of the spinal canal and improper expanded range of the spinal canal. Posterior revision surgeries, such as ODL, LCF, and laminectomy of responsible lamina, could guarantee fine clinical results.

Anterior Cervical Corpectomy and Fusion Versus Posterior Laminoplasty for Cervical Oppressive Myelopathy Secondary to Ossification of the Posterior Longitudinal Ligament: A Meta-analysis

The purpose of this study was to compare the clinical effect of anterior cervical corpectomy with fusion vs laminoplasty for cervical ossification of the posterior longitudinal ligament. The outcome measures included the Japanese Orthopaedic Association score, neurological recovery rate, and complication rate. Subgroup A represented studies with the mean preoperative canal occupying ratio being less than 50%, whereas subgroup B represented studies with the mean canal occupying ratio being 50% or greater. In subgroup A, no difference was found between the 2 groups in the postoperative Japanese Orthopaedic Association score and neurological recovery rate. In subgroup B, the anterior cervical corpectomy with fusion group had a higher postoperative Japanese Orthopaedic Association score and neurological recovery rate. The authors recommend anterior cervical corpectomy with fusion for cervical ossification of the posterior longitudinal ligament when the canal occupying ratio is 50% or greater, and they prefer laminoplasty when the canal occupying ratio is less than 50%. [Orthopedics. 2019; 42(3):e309-e316.].

Selective blocking laminoplasty in cervical laminectomy and fusion to prevent postoperative C5 palsy

BACKGROUND CONTEXT

Cervical laminectomy and fusion (CLF) is a common surgical option for multilevel cord compression. Postoperative C5 palsy occurrence after CLF has been a vexing problem for spine physicians. The posterior shift of the cord following laminectomy has been implicated as a major factor for postoperative C5 palsy, but attempts by spine surgeons to mitigate excessive shift while providing sufficient decompression have not been well reported.

PURPOSE

To compare the incidence of postoperative C5 palsy after performing selective blocking laminoplasty concurrently with CLF to those of conventional CLF.

STUDY DESIGN

A retrospective comparative study of prospectively collected data.

PATIENT SAMPLE

Of 116 cervical myelopathy patients with degenerative cervical myelopathy, ossification of the posterior longitudinal ligament, and multilevel disc herniation, 93 patients (69 in group A [CLF group] and 24 in group B [selective blocking laminoplasty with CLF, CLF-S group]) were included in the study.

OUTCOME MEASURES

The primary outcome measure was the occurrence of postoperative C5 palsy. Secondary end points included (1) clinical outcomes based on pain intensity, neck disability index (NDI), Japanese Orthopaedic Association (JOA) score, (2) radiologic outcomes including cervical alignment and fusion rate at 1 year and hardware complications, and (3) perioperative data (hospital stay, blood loss, and operative times).

METHODS

We compared the occurrence of postoperative C5 palsy, as well as clinical, radiologic, and surgical outcomes, between the two groups at 1-year follow-up.

RESULTS

The patients in both groups were statistically similar between the groups with respect to demographic characteristics such as age, sex, smoking status, body mass index, preoperative pathology, surgical segments, and the degree of the cervical lordosis. Postoperative C5 palsy developed in 9 of 61 patients (14%) in group A and in 0 of 24 patients (0%) in group B (CLF-S group) (p=.03). Postoperative neck pain, NDI, and JOA improvement were not significantly different between the two groups (p=.93, 0.90, and 0.79, respectively). Perioperative data did not differ significantly between the two groups.

CONCLUSIONS

This study showed that performing selective blocking laminoplasty might lead to reducing the incidence of postoperative C5 palsy in CLF surgery.

Perioperative complications of anterior decompression with fusion versus laminoplasty for the treatment of cervical ossification of the posterior longitudinal ligament: propensity score matching analysis using a nation-wide inpatient database

BACKGROUND CONTEXT

Surgical treatment of cervical ossification of the posterior longitudinal ligament (OPLL) has a high risk of various complications. Anterior decompression with fusion (ADF) and laminoplasty (LAMP) are the most representative surgical procedures. However, few studies have compared the two procedures in terms of perioperative surgical complications.

PURPOSE

To compare the perioperative complications post-ADF and LAMP for cervical OPLL using a large national inpatient database.

STUDY DESIGN

A retrospective cohort study with propensity score matching analysis.

PATIENT SAMPLE

Overall, 8,718 (ADF/LAMP:1,333/7,485) patients who underwent surgery for cervical OPLL from April 1, 2010 to March 31, 2016 in hospitals using the diagnosis procedure combination were analyzed.

OUTCOME MEASURES

The occurrence of postoperative complications during hospitalization.

METHODS

We compared the perioperative systemic and local complications, reoperation rates, and costs between ADF and LAMP using propensity score matching analysis.

RESULTS

One-to-one matching resulted in 1,192 pairs of patients who underwent ADF and LAMP. The postoperative cardiovascular event rate was significantly higher (ADF/LAMP=1.9/0.8%, p=.013) in the ADF group. The incidence rates of dysphagia (similarly, 2.4/0.2%, p<.001), pneumonia (1.0/0.3%, p=.045), and spinal fluid leakage (2.4/0.4%, p<.001) were also higher in the ADF group, even after matching. The costs were also higher in the ADF group. However, surgical site infection (2.0/3.4%, p=.033) was significantly lower in the ADF group. No significant difference in the reoperation rates was found between the groups.

CONCLUSION

The present study, using a large nationwide database, demonstrated that perioperative complications were more common in the ADF group, but that surgical site infection (SSI) was more frequently observed in the LAMP group.

Preoperative severity of facet joint degeneration does not impact the 2-year clinical outcomes and cervical imbalance following laminoplasty

BACKGROUND CONTEXT

The impact of preoperative facet degeneration (FD) on surgical outcomes following laminoplasty has not been established.

PURPOSE

To elucidate the influence of preoperative FD on pre and postoperative clinical symptoms and radiographic parameters.

STUDY DESIGN

Retrospective analysis of prospectively collected data.

PATIENT SAMPLE

A total of 135 consecutive patients who underwent laminoplasty for cervical spondylotic myelopathy with greater than 2 years follow-up.

OUTCOME MEASURES

The cervical Japanese Orthopedic Association score, visual analog scale, Short Form-36, Japanese Orthopedic Association Cervical Myelopathy Evaluation Questionnaire, and radiographic parameters (C7 slope, C2-C7 sagittal vertical axis, C2-C7 lordotic angle, and scoring of FD).

METHODS

FD severity of the bilateral facets of C2-3 to C7-T1 was graded using preoperative computer tomography images. Patients were divided into two quantiles according to the mean score of their FD grading: mild (n=69) and severe FD groups (n=66). The preoperative clinical score and radiographic parameters of the two groups were compared. Variables with p<.05 were included in the multinomial logistic regression model. The changes in clinical scores and radiographic parameters between both groups (from the preoperative to 2-year postoperative period) were compared using a mixed-effect model, after adjusting for age and sex.

RESULTS

Mean age and neck pain visual analog scale were independently associated with FD severity (age: p=.004, neck pain: p=.004). However, the other preoperative clinical scores and radiographic parameters were not significantly different. In terms of the change in clinical scores 2 years postlaminoplasty, no significant differences between the severe and mild FD groups were noted. While the mild FD group had a reduced C2-C7 lordotic angle, the severe FD group demonstrated an increased C2-C7 lordotic angle 2 years postlaminoplasty (p=.044). The change in C7 slope and C2-C7 sagittal vertical axis showed no significant differences.

CONCLUSIONS

Preoperative FD severity did not influence the 2-year surgical outcomes of laminoplasty, in terms of improvement in myelopathy, patient-oriented score of quality of life, physical and mental status, as well as neck pain. Furthermore, preoperative FD severity correlated with neither preoperative cervical imbalance nor balance deterioration after laminoplasty. These results may encourage physicians to consider laminoplasty for patients with cervical spondylotic myelopathy, regardless of the severity of FD.

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.

Cervical Open-Door Laminoplasty by Hydroxyapatite Implant Insertion Without Suturing

OBJECTIVE

To assess the efficacy of cervical open-door laminoplasty by hydroxyapatite implant insertion between the lamina and the lateral mass without suturing.

METHODS

All patients who underwent cervical open-door laminoplasty with C2/C7 undermining and insertion of hydroxyapatite implants from C3 to C6 were retrospectively evaluated for surgical time and neurological outcomes according to the Japanese Orthopaedic Association (JOA) score. To assess the alignment of the cervical spine and postoperative cervical pain, the C2-7 angle and a visual analogue scale score were used, respectively.

RESULTS

The population consisted of 102 women and 222 men ranging in age from 32 to 90 years. The average surgical time was 86 minutes. Fourteen of 1,296 hydroxyapatite implants were kept in place with sutures due to a weak restoration force of the hinge during surgery. No hydroxyapatite implant dislocation was detected on cervical computed tomography at 1 year after surgery. The average JOA score was 10.2±2.5 before surgery and 14.6±2.8 at 1 year after surgery. The average recovery rate was 61.8%. The average C2-7 angle at the neutral position was 7.1°±6.2° before surgery and 6.5°±6.3° at 1 year after surgery.

CONCLUSION

This method enabled us to achieve minimal exposure of the lateral mass, prevention of lateral mass injury and dural injury, and a shorter surgical time while maintaining acceptable surgical outcomes. The idea that firm suture fixation is needed to prevent spacer deviation during cervical open-door laminoplasty may need to be revisited.

Clinical and radiological outcomes following open door laminoplasty: a single center evolution of the technique

BACKGROUND

A comparison of clinical and radiological outcomes after two different variants of open door laminoplasty for cervical spondylotic myelopathy (CSM) is described.

METHODS

Fifty-five patients underwent cervical laminoplasty for CSM. Between 2005 to 2009, 32 patients underwent open-door laminoplasty (Group A) performed with a monolateral exposure with contralateral "green stick" laminar fracture. A technical variant consisting in bilateral exposure, spinous process removal and symmetrical muscular closure was applied in the other 23 (Group B), from 2009 to 2016. A retrospective analysis of surgical results between the two groups was performed.

RESULTS

In group B, the mean operative time was longer and the mean volume of intraoperative blood loss was much higher than in group A. Both differences were not significant (p=0.1601 and p=0.0884, respectively). The average hospitalization was nonsignificantly longer in group B (7.3±1.8 vs. 6.5±1.6 d; p= 0.0947). Postoperatively, axial neck pain was more severe in group A at last follow-up than preoperatively (P>0.05). mJOA scores and Nurick grades improved significantly in both groups at last follow-up; in group A, the mean recovery rates were 41.5 % by mJOA scores and 29.4 % by Nurick grades, whereas in group B they were 52.7 % and 36.8 %, respectively.

CONCLUSIONS

Applying some few variations to a standard monolateral approach, although slightly more time and blood consuming, could reduce the incidence of long term axial symptoms and, in our experience, are not burdened by worsening of outcomes. A prospective, multicentric study with a longer follow-up should be conducted in order to confirm our findings.

Risk Factor Analysis of Change in Intraoperative Neurophysiologic Monitoring During Cervical Open Door Laminoplasty

OBJECTIVE

The aim of this study is to determine the risk factors affecting intraoperative neurophysiologic monitoring (IONM) changes, when such changes take place, and clinical outcomes associated with IONM change during cervical open door laminoplasty (COL) for cervical compressive myelopathy.

METHODS

Between 2010 and 2015, 79 patients who underwent COL with IONM recording were studied. Changes in motor evoked potentials or somatosensory evoked potentials over an alarm criterion were defined as IONM change. Patients with IONM change were assigned to the alarm group, and the others were classified as the control group. Baseline data and radiographic measurements were compared between the 2 groups. Radiologic parameters including maximal compression level (MCL), area and diameter of the spinal canal and ventral compressive lesion, stenosis grade, and occupying ratio of area (ORA) and length at the MCL were measured with magnetic resonance imaging.

RESULTS

Thirteen patients were assigned to the alarm group and 66 patients were assigned to the control group. Multivariate analysis identified ORA at the MCL (odds ratio, 1.520; 95% confidence interval, 1.192-1.37; P = 0.001) as an independent risk factor for IONM change. Immediately after decompression, the IONM change occurred. One of 4 patients who did not fully recover from the IONM change had postoperative motor deficits.

CONCLUSIONS

IONM change during COL occurred immediately after decompression, and a risk factor of IONM change was ORA at the MCL. If the IONM change was not fully recovered, a new motor deficit occurred after COL.

The K-line in the cervical ossification of the posterior longitudinal ligament is different on plain radiographs and CT images

BACKGROUND

The K-line, which is a virtual line between the midpoints of the antero-posterior canal diameter at C2 and C7, can be useful for determination of surgical procedures for cervical ossification of the posterior longitudinal ligament (OPLL). Although K-line is originally measured with plain radiogram, computed tomography multiplanar reconstruction (CT-MPR) is applied for K-line measurement by several surgeons. The purpose of the present study was to analyze whether there is a difference in K-lines obtained from radiographs of standing patients and those obtained from CT-MPR images of supine patients.

METHODS

The present study included 65 patients with cervical OPLL underwent surgical treatment. We investigated the K-line (+ or -) before surgery, measured from lateral cervical spine radiographs taken in standing patients in a neutral position (X-P-based K-line) and CT-MPR mid-sagittal images obtained in supine patients (CT-based K-line). The X-P-based and CT-based K-lines were compared and differences between them were assessed.

RESULTS

The-X-P-based K-line was found to be (+) in 35 patients and (-) in 30 patients. Four of 35 patients with an X-P-based K-line (11%) showed a change from K-line (+) to (-) in CT-based K-line measurements. One of 30 patients with an X-P-based K-line (3%) showed a change from (-) to (+) in CT-based measurements.

CONCLUSIONS

The K-line should be measured with plain radiogram of standing patients because X-P-based K-line and CT-based K-line can be different.

Radiological manifestations and surgical outcome of combined upper cervical cord compression and cervical ossification of the posterior longitudinal ligament with a minimum 2-year follow-up

Combined upper cervical cord compression associated with cervical ossification of the posterior longitudinal ligament (OPLL) is a rare and under-recognized disorder. The aim of this study was to investigate the radiological manifestations and surgical outcome of this combined disease.Between May 2011 and July 2015, patients who underwent surgery for combined upper cervical cord compression and cervical OPLL in our institution were included in this study. After a minimum 2-year follow-up, radiological and clinical data were collected. The etiology of upper cervical cord compression and radiological features of cervical OPLL was determined. Surgical outcome was evaluated with Visual Analogue Scale (VAS), Japanese Orthopedic Association score (JOA), space available for the spinal cord (SAC) at the cephalad adjacent level, occupying ratio of OPLL and cervical lordosis.In total, 24 patients (11 men and 13 women) with a mean age of 57.9 years old were included. The etiology of upper cervical cord compression included craniovertebral junction deformity (n = 10), atlantoaxial subluxation (n = 5), and OPLL extending to C2 level (n = 9). The extent, type, and thickest level of cervical OPLL varied among the patients. Significant improvement of VAS and JOA score was noted postoperatively and at a minimum 2-year follow-up. The result was satisfactory in SAC at the cephalad level and occupying ratio of OPLL. There were no significant differences in C2/C7 lordotic angle at the preoperative, postoperative and the last follow-up examination.In conclusion, the radiological manifestations of combined upper cervical cord compression and cervical OPLL varied among the patients. Satisfied results can be achieved with adequate surgical treatment a minimum 2-year follow-up.

Preoperative Risk Factors of C5 Nerve Root Palsy After Laminectomy and Fusion in Patients With Cervical Myelopathy: Analysis of 70 Consecutive Patients

STUDY DESIGN

A retrospective study.

OBJECTIVE

To identify preoperative risk factors causing cervical fifth nerve root palsy (C5 palsy) after laminectomy and fusion (LF).

SUMMARY OF BACKGROUND DATA

It is well known that postoperative C5 palsy is not rare after cervical surgery. Although there remains controversy, C5 palsy is considered to be more common in patients who had LF than in those who had laminoplasty. However, the reason for the higher incidence of C5 palsy in patients with LF has been poorly understood.

METHODS

A total of 70 consecutive patients (mean age: 60.3 y) who had LF due to cervical myelopathy were reviewed. Patients were divided on the basis of the presence (group P) or absence (group N) of C5 palsy. Among various risk factors for C5 palsy from previous reports, 6 risk factors were selected as follows: (1) preoperative low Japanese Orthopedic Association score, (2) postoperatively increased lordosis, (3) low Pavlov ratio, (4) high signal intensity in the cord at C3-C5, (5) anterior protruding mass lesion compressing the spinal cord, and (6) presence of C4-C5 foraminal stenosis. With these factors, the 2 groups were compared by statistical analysis.

RESULTS

C5 palsy occurred in 10 patients (14.3%). The mean onset time was 3.5 days (range, 1-8 d) and the mean recovery time was 3.4 months (range, 1-7 mo). There were no significant differences in the preoperative Japanese Orthopedic Association score, cervical lordosis, Pavlov ratio, high signal intensity, and anterior protruding mass between the 2 groups (P>0.05). However, C4-C5 foraminal stenosis was found in 80.0% (8/10) in group P and 21.7% (13/60) in group N. There were significant differences between the 2 groups in C4-C5 foraminal stenosis (P=0.004).

CONCLUSIONS

In this study, a high occurrence rate and risk factor for C5 palsy were verified after LF. Among the various factors, C4-C5 foraminal stenosis was the only risk factor for C5 palsy. Preoperative warning for C5 palsy after LF seems to be imperatively necessary, especially in patients with C4-C5 foraminal stenosis.

Why Does C5 Palsy Occur After Prophylactic Bilateral C4-5 Foraminotomy in Open-Door Cervical Laminoplasty? A Risk Factor Analysis

STUDY DESIGN

Retrospective study.

OBJECTIVES

To evaluate the efficacy of bilateral C4-5 foraminotomy in preventing occurrence of postoperative C5 palsy and to identify possible risk factors for its development.

METHODS

A total of 70 consecutive patients who underwent open-door laminoplasty with bilateral C4-5 foraminotomy were included. Clinical, radiographic, and operative data was reviewed. Development of postoperative C5 palsy was analyzed.

RESULTS

A total of 54 males and 16 females were reviewed. Mean age was 56 years (range, 30-86 years). The primary pathology was spondylosis in 76% of cases and ossified posterior longitudinal ligament in 21%. Radiographic evidence of C4-5 foraminal stenosis was seen in 81% of the patients. The mean duration of preoperative symptoms was 7 ± 19 months. Four (5.7%) out of 70 patients developed C5 palsy after open-door laminoplasty with bilateral C4-5 foraminotomy. Multivariate analysis showed that a long duration of preoperative symptoms (>12 months) and the presence of preoperative C4-5 T2-MRI cord signal change were statistically significant risk factors for the development of C5 palsy even after bilateral C4-5 foraminotomy in open-door laminoplasty (P < .0001 and P = .036, respectively).

CONCLUSIONS

Prophylactic bilateral C4-5 foraminotomies do not completely eliminate the occurrence of C5 palsy. Prolonged duration of symptoms and presence of preoperative T2-MRI cord signal change increase the risk for developing postoperative C5 palsy despite foraminotomy.

Scarcity of Implants Has Partially Replaced Cervical Spondylotic Myelopathy Decompression and Instrumented Fusion with Implant-Less Expansile Cervical Laminoplasty: Poverty Teaches all the Arts

OBJECTIVE

The scarcity of implants during the economic crisis partially has replaced decompression and instrumented fusion for the treatment of cervical spondylotic myelopathy with implant-less expansile cervical laminoplasty (ECL). The aim of the study was to compare the results obtained with instrumented anterior cervical corpectomy and fusion with implant-less ECL.

METHODS

Patients suffering from cervical spondylotic myelopathy Nurick 3-5 with preoperative tethering and postoperative untethering were included. Exclusion criterion was kyphosis more than 10°. Patients were assessed according to 30-meter walking track (30mWT), Nurick, and modified Japanese Orthopaedic Association scale scores. Kinematic magnetic resonance imaging 3-dimensional subaxial spinal cord reconstructions were 3 dimensionally modeled to confirm preoperative pincer clamping and follow-up unclamping to measure subaxial spinal cord length and pia envelope area (PEA).

RESULTS

A total of 35 patients divided in the ECL (n = 19) and the anterior cervical corpectomy and fusion (n = 16) groups were selected from 534 patients operated on between September 1, 2008, and August 31, 2013 as the result of degenerative cervical disorders. Patients improved according to Nurick and modified Japanese Orthopaedic Association scores without differences between groups. Follow-up 30mWT analysis showed greater decrease in steps number and time in ECL group, creating the basis for further imaging analysis. Magnetic resonance imaging analysis showed that spinal cord length (mm) shortened more (4.47 ± 1.87 vs. 1.5 ± 2.5, t = -4.02; P = 0.0003) and PEA (mm²) shrank more (95.58 ± 43.73 vs. 22.94 ± 33.11, t = -5.45, P < 0.0001) in the ECL group. Multivariate logistic analysis showed that Δ 30mWT-time and Δ PEA were a very predictive model when area under the receiver operating characteristic curve is 0.98.

CONCLUSIONS

Our results created a nidus for further research of postdecompression spinal cord relaxation.

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

BACKGROUND CONTEXT

Although several laminar fixation methods in expansive open-door laminoplasty (EODL) have been reported, the differences in outcomes between the methods have not been well understood.

PURPOSE

The aim of this study were to investigate the impact of laminar fixation methods and cervical spine alignment after EODL on clinical and radiological outcomes, and to investigate the impact of laminar closure on clinical outcomes.

STUDY DESIGN

This study is a retrospective review of clinical and radiological data.

PATIENT SAMPLE

The inclusion criteria were having undergone EODL with suture anchor (n=74, Anchor group) or hydroxyapatite spacers (n=65, Spacer group) for cervical spondylotic myelopathy (CSM). Different surgical procedures were used during two time periods: anchor technique from 2001 to 2006, and spacer technique from 2007 to 2012.

OUTCOME MEASURES

Japanese Orthopaedic Association (JOA) scores for cervical myelopathy were recorded. Cross-sectional areas (CSA) were measured preoperatively, and at 1 week, 6 months, and 2 years postoperatively at each level (C3-C6) using reconstructed axial computed tomography (CT) images. The CSA decrease of more than 20% was defined as laminar closure.

METHODS

The JOA scores and the CSA values were compared between the two groups (Anchor group vs. Spacer group) and subgroups (preoperative kyphosis vs. lordosis alignment, closure vs. non-closure groups).

RESULTS

In both groups, the mean CSA decreased at 6 months postoperatively compared with that at 1 week postoperatively. The CSA further decreased at 2 years postoperatively in the Anchor group but remained unchanged after 6 months in the Spacer group. The CSA remained unchanged in patients with preoperative lordosis in both groups. However, patients with kyphosis in the Anchor group showed a continuously decreasing CSA throughout the follow-up period, whereas CSA was stable in patients with kyphosis in the Spacer group (p<.01). Although the preoperative JOA scores did not differ between the closure and non-closure group (p=.924), the JOA score was significantly worse in the closure group at 1 and 2 years postoperatively (p=.023 and p=.011 respectively).

CONCLUSIONS

The patients with CSM with kyphosis in the Spacer group experienced significantly less laminar closure after EODL compared with patients in the Anchor group. Laminar closure greater than 20% was associated with poor outcome. Therefore, spacer fixation is preferable to anchor screw fixation during EODL in patients with kyphosis.

En Bloc Cervical Laminoplasty Using Translaminar Screws (T-laminoplasty): Novel Procedure for Preserving Midline Ligamentous Structures

STUDY DESIGN

Prospectively maintained and retrospectively analyzed study.

OBJECTIVE

The authors have newly developed an en bloc cervical laminoplasty using translaminar screws (T-laminoplasty) to preserve the posterior midline structures so as to maintain spinal stability and prevent postoperative axial pain and deformity.

SUMMARY OF BACKGROUND DATA

Cervical laminoplasty is a popular surgical procedure for patients with multilevel compressive cervical lesions. However, several reports have noted its limitations and shortcomings.

METHODS

After exposure of the posterior cervical spine with preservation of the midline ligamentous structure, en bloc laminotomy was performed and made a laminectomized block. While the laminotomized block was being lifted, the translaminar trajectory from the lamina to the contralateral lateral mass was prepared. Then a translaminar screw was inserted with suspension of the laminotomized block to expand the spinal canal, passed through the laminar spacer, and finally fixed in the contralateral lateral mass. Next, another screw was inserted into the adjacent segment from the opposite side, and further screw fixations were made in this alternating manner.

RESULTS

Twenty patients underwent T-laminoplasty and 83 segments were operated upon. Clinical outcomes were statistically improved during the mean follow-up period of 19.7 months. Radiologic outcomes of cervical lordosis and range of motion were preserved with the expansion of the cross-sectional area of the spinal canal. In addition, no restenosis or laminar settlement was observed at the last follow-up.

CONCLUSIONS

T-laminoplasty can be one of the surgical options for multilevel compressive cervical lesions. With midline ligamentous structures preserving the procedure, it was possible to get enough canal decompression and foraminal decompression, while obtaining good clinical and radiologic outcomes.

Use of Miniplates and Local Bone Grafts to Prevent Spring Back in Laminoplasty for Cervical Spondylotic Myelopathy

Background/Purpose

Cervical spondylotic myelopathy/ossification of posterior longitudinal ligament can be treated by anterior or posterior decompression. For multiple levels, it is common to perform posterior decompression by laminoplasty. Hirabayashi described his open-door expansive laminoplasty in 1977, which soon became popular. Spring back of the lamina has always been a problem. Many methods including suturing to soft tissue, suture anchors, bone grafts, hydroxyapatite blocks, and ceramic spacers were used to prevent this problem, but with considerable failure. Recently, miniplates were used to prevent spring back.

Methods

Twenty-nine consecutive patients who had underwent Hirabayashi open-door expansive laminoplasty in a single centre were recruited in this retrospective study. Miniplates were used to keep the laminae open. In addition, the spinous processes of lower cervical vertebrae were excised and used as local bone grafts to fill the gap between the cut laminae. Computerized tomography scans were performed postoperatively for all patients to assess bone union and spring back.

Results

A total of 126 levels of laminoplasty and 51 local bone grafts were studied. The minimal follow-up period was 12 months. Signs of bone union were demonstrated in 123 hinges (97.6%) and 51 bone grafts (100%). No spring back was detected. The clinical outcome in terms of Hirabayashi recovery rate was 47.2%.

Conclusion

Miniplates and local bone grafts are promising and effective tools for preventing spring back in cervical laminoplasty.

Comparison of Functional and Radiological Outcomes Between Two Posterior Approaches in the Treatment of Multilevel Cervical Spondylotic Myelopathy

BACKGROUND

Posterior cervical decompression is an accepted treatment for multilevel cervical spondylotic myelopathy (CSM). Each posterior technique has its own advantages and disadvantages. In the present study, we compared the functional and radiological outcomes of expansive hemilaminectomy and laminoplasty with mini titanium plate in the treatment of multilevel CSM.

METHODS

Forty-four patients with multilevel CSM treated with posterior cervical surgery in Department of Orthopedic Surgery, Beijing Army General Hospital from March 2011 to June 2012 were enrolled in this retrospective study. Patients were divided into two groups by surgical procedure: Laminoplasty (Group L) and hemilaminectomy (Group H). Perioperative parameters including age, sex, duration of symptoms, operative duration, and intraoperative blood loss were recorded and compared. Spinal canal area, calculated using AutoCAD ® software(Autodesk Inc., San Rafael, CA, USA), and neurological improvement, evaluated with Japanese Orthopedic Association score, were also compared.

RESULTS

Neurological improvement did not differ significantly between groups. Group H had a significantly shorter operative duration and significantly less blood loss. Mean expansion ratio was significantly greater in Group L (77.83 ± 6.41%) than in Group H (62.72 ± 3.86%) (P < 0.01).

CONCLUSIONS

Both surgical approaches are safe and effective in treating multilevel CSM. Laminoplasty provides a greater degree of enlargement of the spinal canal, whereas expansive hemilaminectomy has the advantages of shorter operative duration and less intraoperative blood loss.

Efficacy of Posterior Segmental Decompression Surgery for Pincer Mechanism in Cervical Spondylotic Myelopathy: A Retrospective Case-controlled Study Using Propensity Score Matching

STUDY DESIGN

Retrospective case-controlled study using propensity score matching.

OBJECTIVE

We aimed to evaluate the efficacy of cervical microendoscopic laminoplasty (CMEL) of the articular segment in patients with cervical spondylotic myelopathy (CSM) by comparing the clinical results of CMEL with conventional expansive laminoplasty (ELAP) for CSM.

SUMMARY OF BACKGROUND DATA

A total of 259 patients undergoing CMEL or ELAP surgery for CSM at authors' institute were reviewed.

METHODS

The patients were matched according to calculated propensity scores in a logistic regression model adjusted for age, sex, and preoperative severity of disorders and divided into the CMEL and ELAP groups. All patients were followed postoperatively for more than 2 years. The preoperative and 2-year follow-up evaluations included neurological assessment (Japanese Orthopaedic Association [JOA] score), recovery rates, the JOA Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), axial pain (visual analog scale), and the Short Form 36 questionnaire (SF-36).

RESULTS

There were 71 patients in each group (47 males and 24 females each). The mean ages of the CMEL and ELAP groups were 63.8 and 62.8 years, respectively. There was no significant difference in the preoperative JOA score between groups. The mean numbers of surgically affected levels in the ELAP and CMEL groups were 3.2 and 1.8 discs, respectively (P ≤ 0.05). The groups exhibited similar recoveries of JOA, JOACMEQ, and SF-36 scores postoperatively. Sagittal alignment was maintained in both groups. However, postoperative neck axial complaints were significantly reduced in the CMEL group.

CONCLUSION

CMEL may be a useful and effective surgical procedure for CSM, providing similar results as ELAP. CMEL for CSM is indicated for posterior decompression of the articular segment along with a pincer mechanism. This minimally invasive technique may have potential advantages compared with conventional ELAP, and may provide an alternative surgical option.

LEVEL OF EVIDENCE

4.

Screw Back-Out Following "Open-Door" Cervical Laminoplasty: A Review of 165 Plates

STUDY DESIGN

Retrospective study.

PURPOSE

To investigate safety profile of open door laminoplasty plates.

OVERVIEW OF LITERATURE

Few reports have documented potential complications related to the use of cervical laminoplasty plates.

METHODS

Records and radiographs of consecutive plated laminoplasty patients of one academic surgeon were analyzed. Group 1 had screw back-out, defined as change in screw position, and group 2 did not.

RESULTS

Forty-two patients (mean age, 56.9) underwent "open-door" cervical laminoplasty using 165 plates. Mean follow-up was 24 months (range, 12-49 months). Mean Nurick grade improved from 2.1 to 0.9 postoperatively. Cervical lordosis (C2-7) was 12.1° preoperatively and 10.0° postoperatively. Range-of-motion was 27.0° preoperatively and 23.4° postoperatively. Partial screw back-out was noted in 27 of 165 plates (16.4%) and in 34 of 660 screws (5.2%). Of the 34 screws, 27 (79.4%) were at either the most cranial (12/27, 44.4%) or the most caudal (15/27, 55.5%) level. Cranially, 11/12 screws (91.7%) had back-out. Caudally, 9/15 lateral mass screws (60.0%) backed-out versus 6 laminar screws (40.0%). Of the 22 patients with screw back-out, 15 (68.2%) occurred <3 months postoperative and 6 (27.3%) occurred 4-12 months postoperative. No statistical differences were found between group 1 and 2 for age, gender, preoperative and postoperative lordosis, focal sagittal alignment, range-of-motion, or Nurick grade. Despite screw backout in 22 patients, there were no plate dislodgements, laminoplasty closure, or neurological deterioration.

CONCLUSIONS

Although screw back-out may occur with the use of cervical laminoplasty plates, the use of these plates without a bone block appears to be safe and reliable. As screw back-out is most common at the cranial and caudal ends of the laminoplasty, we recommend using the maximum number of screws (typically 2 for the lateral mass and 2 for the spinous process) at these levels to secure the plate to the bone.

Preliminary Experiences of the Combined Midline-Splitting French Door Laminoplasty with Polyether Ether Ketone (PEEK) Plate for Cervical Spondylosis and OPLL

Objective

The purpose of this study was to evaluate the safety and efficacy of cervical midline-splitting French-door laminoplasty with a polyether ether ketone (PEEK) plate. The authors retrospectively analyzed the results of patients with cervical laminoplasty miniplate (MAXPACER®) without bone grafts in multilevel cervical stenosis.

Methods

Fifteen patients (13 males and 2 females, mean age 50.0 years (range 35-72)) with multilevel cervical stenosis (ossification of the posterior longitudinal ligament and cervical spondylotic myelopathy) underwent a combined surgery of midline-splitting French-door laminoplasty with or without mini plate. All 15 patients were followed for at least 12 months (mean follow-up 13.3 months) after surgery, and a retrospective review of the clinical, radiological and surgical data was conducted.

Results

The radiographic results showed a significant increase over the postoperative period in anterior-posterior diameter (9.4±2.2 cm to 16.2±1.1 cm), open angles in cervical lamina (46.5±16.0° to 77.2±13.1°), and sectional volume of cervical central canal (100.5±0.7 cm² to 146.5±4.9 cm²) (p<0.001). The sagittal alignment of the cervical spine was well preserved (31.7±10.0° to 31.2±7.6°, p=0.877) during the follow-up period. The clinical results were successful, and there were no significant intraoperative complications except for screw displacement in two cases. The mini plate constructs did not fail during the 12 month follow-up period, and the decompression was maintained.

Conclusion

Despite the small cohort and short follow-up duration, the present study demonstrated that combined cervical expansive laminoplasty using the mini plate is an effective treatment for multilevel cervical stenosis.

Cervical Laminoplasty: The History and the Future

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

Clinical and radiographic analysis of c5 palsy after anterior cervical decompression and fusion for cervical degenerative disease

STUDY DESIGN

A retrospective cohort study.

OBJECTIVE

To present the cases of 6 patients who developed C5 palsy after anterior decompression and discuss the mechanism of C5 palsy development, especially with respect to radiographic change.

SUMMARY OF BACKGROUND DATA

C5 palsy has been reported to be a major complication of both anterior and posterior decompression procedures. Although several mechanisms of injury have been proposed, few reports have been issued on C5 palsy after anterior decompression surgery.

METHODS

A retrospective medical record review was performed on 134 patients who underwent anterior decompression and fusion in our hospital from 2008 to 2011. C5 paralysis was defined as deterioration in muscle power of the deltoid or biceps brachii by at least 1 grade by manual muscle testing. Clinical features and radiologic parameters were evaluated to identify predisposing factors.

RESULTS

Six patients (4.3%) suffered postoperative paralysis in the upper extremities (C5 radiculopathy). C5 palsy did not occur in 30 patients with radiculopathy. Excluding patients with cervical radiculopathy, the rate of C5 palsies was 5.8% for myelopathy patients. Three of 76 (3.95'%) cervical spondylotic myelopathy cases, one of 6 (16.7%) cervical spondylotic radiculomyelopathy patients, and 2 of 22 (9%) patients with ossification of the posterior longitudinal ligament showed C5 palsy. In 2 of the 6, C5 palsy developed after anterior cervical corpectomy, in 3 patients after anterior cervical discectomy and plate fusion, and in 1 after a standalone cage. Two patients underwent reoperation for foraminal decompression. Of the 4 treated conservatively, 3 fully recovered and the other almost fully improved (grade 4). Of 2 patients treated surgically, 1 showed full improvements. The other had no improvement. Radiographic measurements of these 6 patients showed that lordosis at operated segments increased postoperatively (mean, 6 degrees), and that overall sagittal alignments of the cervical spine (C3-C7) also increased (mean, 8.2 degrees).

CONCLUSIONS

This study suggests that improved lordosis of the cervical spinal column can result in traction injury to the spinal cord and C5 nerve roots and that reoperation does not always produce good results. Methods of preventing and treating C5 palsy after anterior decompression and fusion require more evaluation.

The efficacy of ultrasound-guided extracorporeal shockwave therapy in patients with cervical spondylosis and nuchal ligament calcification

We investigated the effects of extracorporeal shockwave therapy (ESWT) on the rehabilitation of cervical spondylosis with nuchal ligament (NL) calcification under X-ray and ultrasound guidance. Sixty patients with cervical spondylosis and calcification of NL were selected and randomly assigned to three groups: A, B, and C. Patients in Group A received rehabilitation with 20 minutes of hot packs and underwent 15 minutes of intermittent cervical traction three times/week for 6 weeks. Patients in Group B received the same rehabilitation as those in Group A and ESWT (2000 impulses, 0.27 mJ/mm(2)) over the calcified NL guided by X-ray image. Patients in Group C received the same treatment as those in Group B, but the ESWT was guided by musculoskeletal sonography. The therapeutic effects were evaluated by: changes in range of motion (ROM) of the cervical spine including flexion, extension, lateral bending, and rotation; visual analog pain scale; and Neck Disability Index before and after treatment and at follow up 3 months later. We found a significant reduction in pain in each treated group after treatment and at follow up. However, patients in Groups B and C showed more improvements in ROM and neck pain relief after treatment and a decrease in Neck Disability Index. Furthermore, patients in Group C showed better cervical ROM at follow up than Group B. ESWT is an adjuvant treatment in the management of cervical spondylosis with calcification of NL and ultrasound-guided ESWT results in more functional improvements.