Analysis of C5 Palsy After Cervical Open-door Laminoplasty: Relationship Between C5 Palsy and Foraminal stenosis

Morphometric analysis of cervical neuroforaminal dimensions from C2-T1 using computed tomography of 1,000 patients

BACKGROUND

Race and sex differences are not consistently reported in the literature. Fundamentally, anatomical differences of cervical neuroforaminal dimensions (CNFD) amongst these groups would be important to know.

PURPOSE

To establish normative radiographic morphometric measurements of CNFD and uncover the influence of patient sex, race, and ethnicity while also considering anthropometric characteristics.

STUDY DESIGN

Retrospective radiographic morphometric study.

PATIENT SAMPLE

A total of 1,000 patients between 18 and 35 years of age who were free of spinal pathology.

OUTCOME MEASURES

Foraminal height, axial width, and area of cervical neural foramen.

METHODS

Cervical CTs were reviewed to measure CNFD, defined as follows: foraminal height, axial width, and area. Statistical analyses were performed to assess associations between CNFD, and patient height, weight, sex, race, and ethnicity.

RESULTS

CNFD measurements followed a bimodal distribution pattern moving caudally from C2-T1. Irrespective of disc level, cervical CNFD were as follows: left and right widths of 6.6±1.5 and 6.6±1.5 mm, heights of 9.4±2.4 and 9.4±3.2 mm, and areas of 60.0±19.5 and 60.6±20.7 mm2. Left and right foraminal width were highest at C2-C3 and lowest at C3-C4. Left and right foraminal height were highest at C7-T1 and C6-C7, respectively and lowest at C3-C4. Left and right foraminal areas were highest at C2-C3 and lowest at C3-C4. Significant differences were observed for all CNFD measurements across disc levels. CNFD did not vary based on laterality. Significant CNFD differences were observed with respect to patient sex, race, and ethnicity. Male height and area were larger compared to females. In contrast, female foraminal width was larger compared to males. The Asian cohort demonstrated the largest foraminal widths. White and Hispanic patients demonstrated the largest foraminal heights and areas. Black patients demonstrated the smallest foraminal widths, heights, and areas. Patient height and weight were only weakly correlated with CNFD measurements across all levels from C2-T1.

CONCLUSIONS

This study describes 36,000 normative measurements of 12,000 foramina from C2-T1. CNFD measurements vary based on disc level, but not laterality. Contrasting left- versus right-sided neuroforamina of the same level may aid in determining the presence of unilateral stenosis. Patient sex, race, and ethnicity are associated with CNFD, while patient anthropometric factors are weakly correlated with CNFD.

Adult cervical spine deformity: a state-of-the-art review

Adult cervical deformity is a structural malalignment of the cervical spine that may present with variety of significant symptomatology for patients. There are clear and substantial negative impacts of cervical spine deformity, including the increased burden of pain, limited mobility and functionality, and interference with patients' ability to work and perform everyday tasks. Primary cervical deformities develop as the result of a multitude of different etiologies, changing the normal mechanics and structure of the cervical region. In particular, degeneration of the cervical spine, inflammatory arthritides and neuromuscular changes are significant players in the development of disease. Additionally, cervical deformities, sometimes iatrogenically, may present secondary to malalignment or correction of the thoracic, lumbar or sacropelvic spine. Previously, classification systems were developed to help quantify disease burden and influence management of thoracic and lumbar spine deformities. Following up on these works and based on the relationship between the cervical and distal spine, Ames-ISSG developed a framework for a standardized tool for characterizing and quantifying cervical spine deformities. When surgical intervention is required to correct a cervical deformity, there are advantages and disadvantages to both anterior and posterior approaches. A stepwise approach may minimize the drawbacks of either an anterior or posterior approach alone, and patients should have a surgical plan tailored specifically to their cervical deformity based upon symptomatic and radiographic indications. This state-of-the-art review is based upon a comprehensive overview of literature seeking to highlight the normal cervical spine, etiologies of cervical deformity, current classification systems, and key surgical techniques.

Impact of lamina-open side on unilateral open door laminoplasty in patients with degenerative cervical myelopathy

Surgeons should select one side for cervical unilateral open door laminoplasty (UODL). However, few reports suggest proper guidelines for deciding which side to open. The aim of this study is to evaluate the impact of opening side in UODL on dominant cord compressive or symptomatic side. 193 degenerative cervical myeloradiculopathy patients with followed-up more than 2 years were enrolled. In all cases, UODL was performed uniformly on the right side. Patients were sub-grouped based on preoperative dominant 3 characteristics: cord compression, myelopathy symptom and radiculopathy symptom (right, symmetric, left). Pre- and postoperative radiographic and clinical parameters and incidence of postoperative C5 palsy were analyzed and compared among the groups. According to dominant compressive side, there were no significant differences in postoperative radiographic and clinical parameters among three groups. According to dominant myelopathy or radiculopathy symptom side, there were no significant differences of all radiographic and clinical parameters postoperatively, except slightly lower neck VAS in groups of preoperative right dominant myelopathy or radiculopathy symptom side at postoperative 1 month. C5 palsies occurred in twelve patients (6.2%), but the incidences were not different among the groups. Therefore, when performing UODL, the choice of lamina opening side can be left to surgeon's preference.

Optimal timing of referral for nerve transfer surgery for postoperative C5 palsy

OBJECTIVE

Cervical nerve 5 palsy can occur following surgery for cervical spine pathology. The prognosis of C5 palsy is generally favorable, and most patients recover useful function. However, some patients do not recover useful strength. Nerve transfers are a potential effective treatment of postoperative severe C5 palsy. This study aimed to further delineate the natural history of recovery from postoperative C5 palsy, determine whether lack of recovery at specific time points predicts poor recovery prognosis, and thereby determine a reasonable time point for referral to a complex peripheral nerve specialist.

METHODS

The authors conducted a retrospective review of 72 patients who underwent surgery for cervical spondylosis and stenosis complicated by C5 palsy. Medical Research Council (MRC) motor strength grades were recorded preoperatively; immediately postoperatively; at discharge; and at 2 weeks, 3 months, 6 months, and 12 months postoperatively. Univariate and multivariate logistic regression models were used to identify demographic and clinical risk factors associated with recovery of useful strength after severe C5 palsy.

RESULTS

The mean patient age was 62.5 years, and 36.1% of patients were female. Thirty patients (41.7%) experienced severe C5 palsy with less than antigravity strength (MRC grade 2 or less) at discharge. Twenty-one (70%) of these patients recovered useful strength (MRC grade 3 or greater) at 12 months postoperatively, and 9 patients (30%) did not recover useful strength at 12 months. Of those patients with persistent severe C5 palsy at 3 months postoperatively, 50% recovered useful strength at 12 months. Of those patients with persistent severe C5 palsy at 6 months postoperatively, 25% recovered useful strength at 12 months. No patient with MRC grade 0 or 1 strength at 6 months postoperatively recovered useful strength. A history of diabetes was associated with the occurrence of severe C5 palsy. On multivariate analysis, female sex was associated with recovery of useful strength.

CONCLUSIONS

Most patients with severe C5 palsy recover useful strength in their C5 myotome within 12 months of onset. However, at 3 months postoperatively, patients with persistent severe C5 palsy had only a 50% chance of recovering useful strength by 12 months. Lack of recovery of useful strength at 3 months postoperatively is a reasonable time point for referral to a complex peripheral nerve center to establish care and to determine candidacy for nerve transfer surgery if severe C5 palsy persists.

Neurological Disturbance of the Upper Extremities After Cervical Laminoplasty: A Morphological Assessment Focused on the Intervertebral Foramen

STUDY DESIGN

A retrospective study.

OBJECTIVE

The aim of this study was to explore the relationship between postoperative neurological disturbance of the upper extremities (NDUE) after cervical laminoplasty and intervertebral foraminal stenosis.

SUMMARY OF BACKGROUND DATA

The relationship between foraminal stenosis and neurological disturbance in the C5 segment (C5 palsy) has been reported, but the relationship at other levels has not been examined before. We evaluated foraminal stenosis morphologically using three-dimensional computed tomography (3D-CT), alongside other risk factors for NDUE.

METHODS

We retrospectively reviewed patients treated by open-door laminoplasty at the authors' institution between January and June 2016. NDUE was defined as postoperative motor deterioration and/or newly emerged sensory disturbance within 2 weeks of surgery. Radiological measurements were performed in bilateral intervertebral foramina from C5 to C8, using 3D-CT. Investigation using magnetic resonance imaging (MRI) was also performed.

RESULTS

Thirty-one patients were reviewed, and 10 (32.3%) developed NDUE. Nineteen NDUE were observed: seven were in the C5 segment, five in the C6 segment, three in the C7 segment, and four in the C8 segment. Four patients (40%) had NDUE from multiple segments. The mean width of the foramen was 2.60 ± 1.26 mm and 3.66 ± 1.66 mm (P = 0.007), and cross-sectional area was 32.8 ± 10.8 mm and 41.6 ± 12.4 mm (P = 0.003), in symptomatic (n = 19) and nonsymptomatic (n = 187) foramina, respectively. The mean transverse diameter of bony spurs and the maximum shift of the spinal cord on MRI was significantly larger in the NDUE group. The odds ratio of having a foraminal cross-sectional area under 28.0 mm in combination with a maximum spinal shift over 3.10 mm was 14.6 (P < 0.001).

CONCLUSION

Stenosis of the intervertebral foramen could be a risk factor for NDUE after cervical laminoplasty, and could be aggravated by excessive posterior spinal cord shift.

LEVEL OF EVIDENCE

3.

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 F2RaD Score: A Novel Prediction Score and Calculator Tool to Identify Patients at Risk of Postoperative C5 Palsy

BACKGROUND

Postoperative C5 palsy is a debilitating complication following posterior cervical decompression.

OBJECTIVE

To create a simple clinical risk score predicting the occurrence of C5 palsy

METHODS

We retrospectively reviewed all patients who underwent posterior cervical decompressions between 2007 and 2017. Data was randomly split into training and validation datasets. Multivariable analysis was performed to construct the model from the training dataset. A scoring system was developed based on the model coefficients and a web-based calculator was deployed.

RESULTS

The cohort consisted of 415 patients, of which 65 (16%) developed C5 palsy. The optimal model consisted of: mean C4/5 foraminal diameter (odds ratio [OR] = 9.1 for lowest quartile compared to highest quartile), preoperative C5 radiculopathy (OR = 3.5), and dexterity loss (OR = 2.9). The receiver operating characteristic yielded an area under the curve of 0.757 and 0.706 in the training and validation datasets, respectively. Every characteristic was worth 1 point except the lowest quartile of mean C4/5 foraminal diameter, which was worth 2 points, and the factors were summarized by the acronym F2RaD. The median predicted probability of C5 palsy increased from 2% in patients with a score of 0 to 70% in patients with a score of 4. The calculator can be accessed on https://jhuspine2.shinyapps.io/FRADscore/.

CONCLUSION

This study yielded a simplified scoring system and clinical calculator that predicts the occurrence of C5 palsy. Individualized risk prediction for patients may facilitate better understanding of the risks and benefits for an operation, and better prepare them for this possible adverse outcome. Furthermore, modifying the surgical plan in high-risk patients may possibly improve outcomes.

Risk factors and preventive measures for C5 palsy after cervical open-door laminoplasty

OBJECTIVE

The pathomechanism of C5 palsy after cervical open-door laminoplasty is unknown despite the relatively common occurrence of this condition postoperatively. The aim of this study was to review clinical and imaging findings in patients with C5 palsy and to propose countermeasures for prevention of this complication.

METHODS

Between 2001 and 2018, 326 patients with cervical myelopathy underwent cervical laminoplasty at the authors' hospital, 10 (3.1%) of whom developed C5 palsy. Clinical features and radiological findings of patients with and without C5 palsy were analyzed.

RESULTS

In patients with C5 palsy, the width of the C5 intervertebral foramen was narrower and the position of the bony gutter was wider beyond the medial part of the C5 facet joint. The distance between the lateral side of the spinal cord and bony gutter was significantly greater in patients with C5 palsy. Patient characteristics, disease, cervical alignment, spinal canal expansion rate, anterior protrusion of the C5 superior articular process, high-intensity area in the spinal cord on T2-weighted MR images, posterior shift of the spinal cord, and operative time did not differ significantly between patients with and without C5 palsy.

CONCLUSIONS

The position of the bony gutter may have a central role in the pathomechanism of postoperative C5 palsy, especially in patients with a narrow C5 intervertebral foramen. Making an excessively lateral bony gutter might be a cause of C5 nerve root kinking at the intervertebral foramen. To prevent the occurrence of C5 palsy, it is important to confirm the medial line of the facet joint on the preoperative CT scan, and a high-speed burr should be started from inside of the facet joint and manipulated in a direction that allows the ligamentum flavum to be identified.

C5 palsy after C5/6/7 posterior foraminal decompression: A case report

RATIONALE

Although C5 palsy is a common complication of cervical spine surgery, its cause has not been confirmed. There are various hypotheses for its mechanism, including spinal cord impairment and nerve involvement. Therefore, prophylactic foraminotomy is one of the methods recommended for preventing C5 palsy. However, we describe a patient who experienced C5 palsy after microendoscopic foraminotomy between the left C5/6 and C6/7 levels.

PATIENT CONCERNS

A 43-year-old man presented with a 14-month history of progressive numbness in the left upper limb. We performed microendoscopic left foraminal decompressions at the C5/6/7 levels to treat the left C6 and C7 radiculopathy. On the postoperative day 1, we observed weak motor strength of the left deltoid, left biceps, and left forearm pronator, while the motor strength of the other muscles was normal.

DIAGNOSES

C5 palsy following C5/6/7 left foraminotomy.

INTERVENTION

Follow-up rehabilitation with muscle strength training and range of motion training.

OUTCOME

The patient recovered his motor strength completely within 3 months postoperatively.

LESSONS

In this case, the C5 palsy could not be adequately explained by the theory of nerve root impingement or disruption in blood circulation following spinal cord decompression. We hypothesized that the patient had drill heat-induced C5 palsy. Regarding the C5 palsy without C5 nerve root decompression, we hypothesize that the C5 palsy in C5/6/7 foraminotomy could be related to variations in the formation of the brachial plexus. Prophylactic foraminotomy for cervical posterior surgery should be performed with care, limiting its use in patients who are at a risk of developing C5 palsy because the prophylactic procedure can cause C5 palsy. We must also consider that even without decompression at the C4/5 level, there is a possibility of C5 palsy occurring.

A Systematic Review of Definitions for Neurological Complications and Disease Progression in Patients Treated Surgically for Degenerative Cervical Myelopathy

STUDY DESIGN

Systematic review.

OBJECTIVE

This review aims to (1) outline how neurological complications and disease progression are defined in the literature and (2) evaluate the quality of definitions using a novel four-point rating system.

SUMMARY OF BACKGROUND DATA

Degenerative cervical myelopathy (DCM) is a progressive, degenerative spine disease that is often treated surgically. Although uncommon, surgical decompression can be associated with neurological complications, such as C5 nerve root palsy, perioperative worsening of myelopathy, and longer-term deterioration. Unfortunately, important questions surrounding these complications cannot be fully addressed due to the heterogeneity in definitions used across studies. Given this variability, there is a pressing need to develop guidelines for the reporting of surgical complications in order to accurately evaluate the safety of surgical procedures.

METHODS

An electronic database search was conducted in MEDLINE, MEDLINE in Process, EMBASE and Cochrane Central Register of Controlled Trials for studies that reported on complications related to DCM surgery and included at least 10 surgically treated patients. Data extracted included study design, surgical details, as well as definitions and rates of surgical complications. A four-point rating scale was developed to assess definition quality for each complication.

RESULTS

Our search yielded 2673 unique citations, 42 of which met eligibility criteria and were summarized in this review. Defined complications included neurological deterioration, late onset deterioration, perioperative worsening of myelopathy, C5 palsy, nerve root or upper limb palsy or radiculopathy, surgery failure, inadequate decompression and progression of ossified lesions. Reported rates of these complications varied substantially, especially those for neurological deterioration (0.2%-33.3%) and progression of ossified lesions (0.0%-86.7%).

CONCLUSION

Reported incidences of various complications vary widely in DCM surgery, especially for neurological deterioration and progression of ossified lesions. This summary serves as a first step for standardizing definitions and developing guidelines for accurately reporting surgical complications.

LEVEL OF EVIDENCE

2.

Anterior versus posterior approach for the therapy of multilevel cervical spondylotic myelopathy: a meta-analysis and systematic review

BACKGROUND

The goal of this meta-analysis is to explore the overall efficacy as well as the safety of anterior versus posterior approach for the therapy of patients with multilevel cervical spondylotic myelopathy based on qualified studies.

METHODS

Three electronic databases, PubMed, Cochrane, Embase were searched updated to January 2018 to identify all relevant and qualified studies using the index words. The qualified studies were including prospective or retrospective comparative studies. Relative risk (RR) and mean difference (MD) along with 95% confidence interval (95% CI) were used to analyze the main outcomes.

RESULTS

In this meta-analysis, there were a total of 24 studies with 959 patients in the anterior approach group and 1072 patients in the posterior approach group. The final results showed, in comparison of the posterior approach group, the anterior approach group significantly increased the JOA score (SMD: 0.36, 95% CI 0.10-0.62), the operation time (WMD: 49.87, 95% CI 17.67-82.08), and the neurological recovery rate (WMD: 10.55, 95% CI 3.99-17.11) with higher complication rate (RR: 1.53, 95% CI 1.24-1.89). Besides, there was no significant difference of the blood loss (SMD: - 0.40, 95% CI - 1.12 to 0.32) and ROM (SMD: - 0.28, 95% CI - 0.78 to - 0.22) between posterior approach group and anterior approach group.

CONCLUSIONS

Studies found a significant increase of JOA score as well as neurological recovery rate by the anterior approach treatment when compared with posterior approach treatment. However, increased operation time and complications could also occur through the anterior approach treatment. More high-quality randomized controlled trials with larger sample size, multi-centric and longer follow-ups are needed to support our current conclusions.

Incidence and Outcomes of C5 Palsy and Axial Pain After Open-Door Laminoplasty or Laminectomy and Fusion: A Meta-Analysis

OBJECTIVE

C5 palsy and axial pain are significant factors affecting the quality of life after posterior cervical surgery; however, there has been no clear and supportive conclusion on which method is more suitable in a certain case. As a result, we compare the clinical outcomes, complication rates, and anatomical changes between open-door laminoplasty (ODL) and laminectomy and fusion (LF) for cervical spondylotic myelopathy. This is a systematic literature review and meta-analysis.

METHODS

A comprehensive literature search was conducted using PubMed, Embase, and the Cochrane library. The following outcomes were extracted and analyzed: the cases of C5 palsy and axial pain patients, Japanese Orthopaedic Association, range of motion (ROM), and cervical curvature. Data analysis was conducted with RevMan 5.3. The I² statistics were used to evaluate heterogeneity.

RESULTS

A total of 9 studies were included in the final analysis, all of which were prospective or retrospective cohort studies. The pooled data showed that the incidences of C5 palsy and axial pain in LF were higher than those in ODL. The study indicated that there was no significant difference in pre- and postoperative Japanese Orthopaedic Association scores, preoperative cervical ROM, pre- and postoperative cervical curvature between the 2 groups, but there was significant difference in ROM after operation. These results indicate that ODL was superior to LF in maintaining cervical ROM.

CONCLUSIONS

Our results demonstrate that the lower incidence of C5 palsy and axial pain can be achieved by using ODL compared with LF. However, current data only provide weak support, if any, favoring ODL over for clinical improvement in reduce these 2 complications.

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.

Simple presurgical method of predicting C5 palsy after cervical laminoplasty using C5 nerve root ultrasonography

OBJECTIVE

The incidence of C5 palsy after cervical laminoplasty is approximately 5%. Because C5 palsy is related to cervical foraminal stenosis at the C4–5 level, the authors hypothesized that cervical foraminal stenosis can be diagnosed by examining the C5 nerve root (NR) using ultrasonography. The purpose of this study was to investigate whether postoperative C5 palsy could be predicted using ultrasonography.

METHODS

This study used a prospective diagnosis design. In total, 140 patients undergoing cervical laminoplasty were examined with ultrasound. The cross-sectional area (CSA) of the C5 NR was measured on both sides before surgery, and the incidence of postoperative C5 palsy was examined. The difference between the CSA of the patients with and without C5 palsy and the lateral differences in the C5 palsy group were determined.

RESULTS

The incidence of C5 palsy was 5% (7 cases). Symptoms manifested at a median of 5 days after surgery (range 1–29 days). The CSA of the C5 NR on the affected side was significantly enlarged in the C5 palsy group compared with that in the no–C5 palsy group (p = 0.001). In addition, in the patients who had C5 palsy, the CSA of the C5 NR was significantly enlarged on the affected side compared with that on the unaffected side (p = 0.02). Receiver operating characteristic analysis indicated that the best threshold value for the CSA of the C5 NR was 10.4 mm2, which provided 91% sensitivity and 71% specificity.

CONCLUSIONS

C5 palsy may be predicted preoperatively using ultrasound. The authors recommend the ultrasonographic measurement of the CSA of the C5 NR prior to cervical laminoplasty.

Short-Term Clinical Evaluation of Enhanced Unilateral Open-Door Laminoplasty Using Titanium Mesh

Study Design

Observational, cross-sectional study.

Purpose

The purpose of this study was to evaluate the clinical efficacy and safety profile of open-door laminoplasty (ODL) using titanium mesh.

Overview of Literature

The most appropriate surgical management of degenerative spine disorders, particularly ossification of the posterior longitudinal ligament, remains controversial and continues unabated in the neurosurgical community. However, recently, ODL has become popular among surgeons. Many modifications have been developed since Hirabayashi in 1983 to enhance the clinical efficacy and safety of this procedure.

Methods

We reviewed the obtained data of patients with ossification of the posterior longitudinal ligament (OPLL) who underwent ODL using titanium mesh at Neurosurgery Subdivision, the Dr. Sardjito Hospital, Yogyakarta, Indonesia, during January 2013–December 2015. Motor improvement (Nurick score), axial neck pain (neck disability index [NDI]), and incidence of complications were pre- and postoperatively examined, and the clinical efficacy and safety of the procedure was evaluated. Data were analyzed using Wilcoxon signed-rank test and paired t-test.

Results

This study included five patients were included (i.e., four males and one female) with mean age of 47.00±9.68 years, where reassessments were done after mean follow up of 20.2±4.74 months. Mean duration of surgery was 165±12.55 minutes. Pre- and postoperative motor assessments were 3.4±1.52 and 2.0±1.22 (p =0.059), respectively. Axial neck pains using NDI were 23.60±7.44 and 12.40±6.50 (p =0.004) before and after operations, respectively. No infected postoperative scar was found, and only one patient had a left C5 motor palsy.

Conclusions

The results of the present study suggest that enhanced ODL using titanium mesh has favorable outcome and safety profile, which can pave the way for a suitable treatment in patients with OPLL.

Differences in Cross-Sectional Intervertebral Foraminal Area From C3 to C7

STUDY DESIGN

Anatomical comparative study.

OBJECTIVES

Few studies have evaluated foraminal areas in the cervical spine without degenerative changes. The purpose of this study was to determine and compare the mean cross-sectional foraminal areas between the C3/4, C4/5, C5/6, and C6/7 levels while also analyzing specimens for differences between sexes and races.

METHODS

We performed an anatomic study of the intervertebral foramen at 4 levels (C3/4, C4/5, C5/6, C6/7) in 100 skeletally mature osseous specimens. Specimens were selected to obtain equal number of African American and Caucasian males and females (n = 25/group) aged 20 to 40 years at time of death. Foramina were photographed bilaterally with and without a silicone rubber disc. The maximal vertical height and mid-sagittal width of each foramen were digitally measured and the areas were calculated using an ellipse as a model.

RESULTS

The average age at death for all specimens was 30 ± 6 years. The mean cross-sectional area of the C4/5 foramen was significantly smaller compared with the C5/6 (P < .001). C5/6 was significantly narrower than C6/7 (P < .001) foramen with and without disc augmentation. C3/4 was not significantly different from more caudal levels. There was no difference between male and female specimens, while African Americans had smaller foraminal sizes than Caucasians.

CONCLUSIONS

This study provides the largest anatomical reference of the cervical intervertebral foramen. In a mature spine without facet joint hypertrophy or osteophytic changes, the C4/5 foramen was narrower than C5/6, which was narrower than C6/7. Understanding the relative foraminal areas in the nonpathological cervical spine is crucial to understanding degenerative changes as well as the anatomical changes in pathologies that affect the intervertebral foramen.

Relationship Between Foraminal Area and Degenerative Changes in the Lower Cervical Spine With Implications for C5 Nerve Root Palsy

Preoperative foraminal stenosis at C4/5 is a predisposing risk factor for C5 nerve root palsy in elderly patients. However, the area of the C4/5 intervertebral foramen and its relationship to the extent of arthrosis and lower foraminal areas (C5/6 and C6/7) are unknown. The authors sought to compare the areas of the cervical intervertebral foramen at the C4/5, C5/6, and C6/7 levels, noting any differences across race or sex and the relationship between foraminal area and arthrosis grade. A total of 600 cervical foramina from an osseous collection were examined. One hundred specimens between the ages of 60 and 80 years were selected, 50 from each sex and race (white and African American). Foramina were photographed bilaterally at C4/5, C5/6, and C6/7. Vertical height and mid-sagittal width were digitally measured. The degree of arthrosis within each intervertebral foramen was graded by 2 of the authors independently using the Kellgren-Lawrence grading system. Average age of death for specimens was 69.3±5.9 years. The mean foraminal areas at C4/5 (P=.001) and C5/6 (P<.001) were significantly smaller than at C6/7. Whites had larger foraminal areas than African Americans at C4/5 (P=.05) and C6/7 (P=.01). Arthrosis grade was found to make a significant contribution to foraminal area at C4/5 (standardized beta=-0.267; P<.001), but not at C5/6 or C6/7. A higher grade of arthrosis was associated with a narrower intervertebral foramen at the C4/5 level in osseous specimens from elderly individuals. [Orthopedics. 2018; 41(4):e506-e510.].

[C5 palsy after multi-segmental cervical decompression : How can it be avoided?]

BACKGROUND

Anterior cervical discectomy and fusion (ACDF) as well as posterior instrumentation of the cervical spine are frequently performed surgeries for cervical disc prolapse or spinal stenosis. Surgery itself harbors a very low risk of adverse events. Postoperative palsy of the C5 nerve root, however, is a severe complication and its origin is still not fully understood. The risk of such a C5 palsy is reported to be between 0 and 30%; 5% on average according to the literature.

OBJECTIVES

To describe underlying pathomechanisms and to recommend strategies for risk reduction.

MATERIALS AND METHODS

An extensive literature research via Medline was performed.

RESULTS

Potential risk factors are male gender, sagittal diameter below 5.6 mm, anterior approach, and higher age.

CONCLUSIONS

Currently available data only originates from retrospective or anatomical studies. A prospective register study with the goal to put light on the pathogenesis is currently being performed.

Clinical Effects of Posterior Longitudinal Ligament Removal and Wide Anterior Cervical Corpectomy for Spondylosis

BACKGROUND

Removing the posterior longitudinal ligament in cervical corpectomy is a controversial issue. It is unclear whether the risks are counterbalanced by clinical benefits. Another unexplored topic is whether the width of the corpectomy affects outcome.

METHODS

This cross-sectional retrospective study included consecutive patients who underwent cervical corpectomy for spondylosis by 6 different neurosurgeons. We compared 2 groups, where the posterior longitudinal ligament was either removed (N = 15 patients) or preserved (N = 21 patients). The posterior width of the corpectomy was assessed postoperatively with computed tomography and magnetic resonance imaging. Clinical results were evaluated with the visual analog scale (VAS), Modified Japanese Orthopedic Association scale (MJOAS), Cooper scale, and neck disability index (NDI), in the long-term follow-up.

RESULTS

Compared to preservation, removal of the posterior longitudinal ligament produced more favorable clinical results (but not statistically significant), based on the VAS (+41%, P = 0.48), MJOAS (+26.5%, P = 0.62), Cooper scale (+19%, P = 0.75), and NDI (+62%, P = 0.22). Magnetic resonance imagings showed that removing the posterior longitudinal ligament produced greater evagination of the dural sac into the space left by the corpectomy. Improvements in clinical outcome were associated with more posterior bone wall removal in the corpectomy (corpectomy width ≥15.6 mm; P < 0.05), based on the VAS, NDI, and MJOAS.

CONCLUSIONS

Removing the posterior longitudinal ligament in cervical corpectomy may produce a better outcome, particularly when associated with more posterior bone wall removal in the corpectomy.

Analysis of C5 palsy in cervical myelopathy with massive anterior compression following laminoplasty

BACKGROUND

Little data is available about comparison of the incidence and clinical characteristics of the C5 palsy between patients of cervical myelopathy with occupying ratio greater than 50% and those with occupying ratio less than 50% following laminoplasty.

METHODS

One-hundred eighteen patients with cervical myelopathy who underwent open door laminoplasty were reviewed in this study. The patients were divided into two groups: group A comprising 55 patients with an anterior occupying ratio greater than 50% and group B comprising 63 patients with an anterior occupying less than 50%. Clinical and radiological outcomes were assessed between two groups.

RESULTS

No statistically difference was found in preoperative Japanese Orthopedic Association (JOA) score of both groups (10.7 ± 1.7 in group A vs 10.9 ± 1.1 in group B, P > 0.05). Improvements in postoperative JOA score were achieved, and there was a statistical difference (14.0 ± 1.4 in group A vs 14.8 ± 0.9 in group B, P < 0.05). Group A had a lower rate of recovery than group B (P < 0.05). Totally, 12 of 118 (10.2%) patients developed the C5 palsy postoperatively. C5 palsy occurred in 3 of 63 patients in the group B compared with 9 of 55 in the group A. Statistically significant difference was found in the incidence of C5 palsy between the two groups (P < 0.05). Furthermore, patients in group A required significantly longer recovery periods than group B. Both preoperative and postoperative MRI presented more levels of T2 high-signal lesion in group A than group B. The degree of posterior shift of the cord after posterior decompression in group A was less than group B (P < 0.05).

CONCLUSIONS

Patients with a high degree of anterior compression have higher risk of C5 palsy than those with a relative low degree of anterior compression.

Incidence of C5 nerve root palsy after cervical surgery: A meta-analysis for last decade

PURPOSE

We aim to perform a meta-analysis on incidence of C5 nerve root palsy (C5 palsy) for patients after cervical surgery.

METHODS

An extensive search of the literature was performed in PubMed/MEDLINE, Embase, the Cochrane library, CNKI, and WANFANG databases on incidence of C5 palsy from January 2007 to January 2017. Prevalence of C5 palsy related to different surgery methods was calculated and data analysis was conducted with STATA 12.0.

RESULTS

A total of 61 studies containing 721 patients with C5 palsy in total 11,481 patients (6.3%) were included in our study. The incidences after anterior cervical discectomy and fusion (ACDF), anterior cervical corpectomy and fusion (ACCF), anterior corpectomy combined with discectomy (ACCDF), laminoplasty (LP) and laminectomy and fusion (LF) were 5.5%, 7.5%, 6%, 4.4%, and 12.2%, respectively. Compared with anterior approaches (5%), female patients (4%) and patients with cervical spondylotic myelopathy (CSM) (4.8%), posterior approaches (6.2%), male patients (5.7%) and patients with ossification of posterior longitudinal ligament (OPLL) (8.1%) have a higher prevalence. In ACDF and LP, patients with OPLL (5.5%, 8.1%, respectively) have a higher incidence than those in patients with CSM (4.7%, 3.1%, respectively); however, in LF, patients with CSM and OPLL have similar incidence of C5 palsy (13% vs 13.1%). In most cases, C5 palsy was unilateral (74.5%).

CONCLUSIONS

Based on our meta-analysis, posterior approaches, male patients and patients with OPLL have a higher incidence of C5 palsy. In ACDF and LP, patients with OPLL have a higher incidence of C5 palsy, but in LF, patients with CSM and OPLL have similar result.

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

PURPOSE

The aim of the present study was to investigate the factors associated with C5 palsy by focusing on radiological parameters using multivariable analysis.

METHODS

The authors retrospectively assessed 190 patients with cervical spondylotic myelopathy treated by open-door laminoplasty. Four radiographic parameters-the number of expanded lamina, C3-C7 angle, lamina open angle and space anterior to the spinal cord-were evaluated to clarify the factors associated with C5 palsy.

RESULTS

Of the 190 patients, 11 developed C5 palsy, giving an overall incidence of 5.8%. Although the number of expanded lamina, lamina open angle and space anterior to the spinal cord were significantly larger in C5 palsy group than those in non-palsy group, a multiple logistic regression analysis revealed that only the space anterior to the spinal cord (odds ratio 2.60) was a significant independent factor associated with C5 palsy. A multiple linear regression analysis indicated that the lamina open angle was associated with the space anterior to the spinal cord and the analysis identified the following equation: space anterior to the spinal cord (mm) = 1.54 + 0.09 × lamina open angle (degree). A cut-off value of 53.5° for the lamina open angle predicted the development of C5 palsy with a sensitivity of 72.7% and a specificity of 83.2%.

CONCLUSIONS

The larger postoperative space anterior to the spinal cord, which was associated with the lamina open angle, was positively correlated with the higher incidence of C5 palsy.

C5 Palsy After Cervical Spine Surgery: A Multicenter Retrospective Review of 59 Cases

STUDY DESIGN

A multicenter, retrospective review of C5 palsy after cervical spine surgery.

OBJECTIVE

Postoperative C5 palsy is a known complication of cervical decompressive spinal surgery. The goal of this study was to review the incidence, patient characteristics, and outcome of C5 palsy in patients undergoing cervical spine surgery.

METHODS

We conducted a multicenter, retrospective review of 13 946 patients across 21 centers who received cervical spine surgery (levels C2 to C7) between January 1, 2005, and December 31, 2011, inclusive. P values were calculated using 2-sample t test for continuous variables and χ² tests or Fisher exact tests for categorical variables.

RESULTS

Of the 13 946 cases reviewed, 59 patients experienced a postoperative C5 palsy. The incidence rate across the 21 sites ranged from 0% to 2.5%. At most recent follow-up, 32 patients reported complete resolution of symptoms (54.2%), 15 had symptoms resolve with residual effects (25.4%), 10 patients did not recover (17.0%), and 2 were lost to follow-up (3.4%).

CONCLUSION

C5 palsy occurred in all surgical approaches and across a variety of diagnoses. The majority of patients had full recovery or recovery with residual effects. This study represents the largest series of North American patients reviewed to date.

Wedge-Shaped Resection of the Posterior Bony Arch During Open Door Laminoplasty to Prevent Postoperative Motion Limitation

STUDY DESIGN

Prospective randomized double-arm noninferiority study.

OBJECTIVE

To evaluate an additional surgical procedure (wedge-shaped resection of the cranial portion of the posterior bony arch) during open-door laminoplasty (ODLP), and to compare the outcomes with those of conventional ODLP surgery.

SUMMARY OF BACKGROUND DATA

In clinical practice, spine surgeons sometimes encounter patients who show bony impingement on lateral radiographs after ODLP; bony impingement may lead to reduced motion of the cervical spine and posterior neck pain. However, this problem has not been well studied, and no methods have been developed to prevent it.

METHODS

Of total 79 patients, 75 were enrolled and randomly assigned to either group A (additional procedure in ODLP, n = 38) or group B (ODLP alone, n = 37). The primary outcome measure was range of motion (ROM) of the cervical spine. Secondary endpoints included clinical outcomes based on pain intensity, 12-item short form health survey (SF-12), and modified Japanese Orthopedic Association scale; presence of bony impingement on dynamic lateral radiographs; surgical outcomes; and surgery-related complications.

RESULTS

ROM of the cervical spine was significantly greater at 6 months (P = 0.04) and 1 year (P = 0.02) postoperative in group A than in group B. Pain intensity at the posterior neck was significantly lower 1 year after surgery in group A than in group B (P = 0.03). In lateral radiographs 1 year after surgery, the presence of posterior bony impingement was 0% in group A and 32.4% in group B (P <0.01). Clinical outcomes and surgery-related complications were similar between groups.

CONCLUSION

Performing wedge-shaped resection of the cranial portion of the posterior bony arch in ODLP surgery can lead to better outcomes than ODLP alone in terms of preservation of cervical ROM, prevention of posterior bony impingement, and amelioration of posterior neck pain.

LEVEL OF EVIDENCE

2.

A Delayed Postoperative C5 Palsy due to Spinal Cord Lesion: A Typical Clinical Presentation but Unusual Imaging Findings

Postoperative C5 palsy (C5 palsy) is a troublesome complication after cervical spine surgery and its etiology is still unclear. We experienced a case of C5 palsy after anterior decompression with fusion for cervical ossification of posterior longitudinal ligament with the typical clinical presentation of left deltoid and bicep weakness and left-arm pain without deterioration of myelopathy symptoms, albeit with the unusual imaging findings not shown preoperatively of a swelling in the spinal cord, and intramedullary high intensity change on T2-weighed MRI. The additional posterior surgery was carried out to decompress the swollen spinal cord. The abnormal findings disappear on MRI taken three weeks following the second surgery and the weakness improved fully within three months after the second surgery. This case report highlights the possibility of spinal cord lesion due to circulatory impairment as a cause of C5 palsy.

C5 nerve root palsy after posterior cervical spine surgery

BACKGROUND

C5 palsy is a serious complication after cervical decompression surgery in which the patient shows a deterioration in power of the deltoid or biceps brachii by at least one grade in the manual muscle test without aggravation of lower extremity function. Although there are several hypotheses regarding the etiology of C5 palsy, the pathogenesis and preventive measures remain unidentified and many other controversies remain.

OBJECTIVE

To systematically review the clinical features, risk factors, mechanism, and preventive measures of C5 palsy after posterior cervical decompression surgery.

MATERIALS AND METHODS

PubMed was searched to identify eligible studies that contained more than 10 cases and focused on C5 palsy. Microsoft Excel was used to analyze the data. Statistical comparisons were made when appropriate.

RESULTS

Out of 718 papers involving C5 palsy, 28 met the inclusion criteria. The average incidence rate was 7.8% (range, 1.4-23.0%). Risk factors for C5 palsy included age, male gender, ossification of the posterior longitudinal ligament, and stenosis of the C4-C5 intervertebral foramen. C5 palsy occurred from immediately to 2 months after surgery, and recovery time ranged from 48 h to 41 months. Hypotheses for the mechanism of C5 palsy included root involvement and spinal cord impairment. Foraminotomy and intraoperative neuromonitoring were the two main methods used to prevent C5 palsy.

CONCLUSION

C5 palsy is a serious complication occurring at the early stage after cervical decompression surgery. Foraminotomy and intraoperative neuromonitoring were the two main methods to prevent C5 palsy. The incidence of C5 palsy is low, but it can place a serious burden on the patients' quality of life and finances. The risk factors and mechanism of C5 palsy are still controversial. However, under conservative therapy, the prognosis is usually good. Higher quality studies are necessary for drawing more reliable and convincing conclusions about this disease.

Cervical Spondylotic Myelopathy

Cervical spondylotic myelopathy (CSM) is a degenerative disease that represents the most common spinal cord disorder in adults. The natural history of the disease can be insidious, and patients often develop debilitating spasticity and weakness. Diagnosis includes a combination of physical examination and various imaging modalities. There are various surgical options for CSM, consisting of anterior and posterior procedures. This article summarizes the literature regarding the pathophysiology, natural history, and diagnosis of CSM, as well as the various treatment options and their associated risks and indications.

A Case of Successful Foraminotomy for Severe Bilateral C5 Palsy following Posterior Decompression and Fusion Surgery for Cervical Ossification of Posterior Longitudinal Ligament

We report a very rare (5~7%) case of bilateral C5 palsy after cervical surgery. A 71-year-old male patient with cervical ossification of posterior longitudinal ligament (OPLL) with foraminal stenosis at bilateral C4/5 underwent posterior decompression and fusion surgery. After surgery, muscle weakness in his both deltoid and biceps was detected and gradually deteriorated to complete paralysis. Postoperative MRI showed sufficient decompression of the spinal cord and posterior shifting. Subsequently, an additional bilateral foraminotomy at C4/5 was performed, with a suspicion that bilateral foraminal stenosis at C4/5 may have been the cause of the paresis. After foraminotomy, muscular contraction was seen in both deltoid and biceps. Finally, complete motor recovery was achieved in a year. Although the gold standard procedure for the prevention and treatment of postoperative C5 palsy has not yet been established, an additional foraminotomy may be recommended for severe C5 palsy in cases of foraminal stenosis even after the occurrence of palsy.

Outcomes and Related Factors of C5 Palsy Following Cervical Laminectomy With Instrumented Fusion Compared With Laminoplasty

STUDY DESIGN

A retrospective study.

OBJECTIVE

The aim of this study was to analyze the clinical outcomes and related factors of C5 palsy (C5P) following posterior cervical laminectomy with fusion (LF) compared with laminoplasty (LP).

SUMMARY OF BACKGROUND DATA

C5P is more common after LF than after LP. There have not been any studies on C5P-LF compared with C5P-LP.

METHODS

We retrospectively analyzed consecutive cases that underwent cervical LF for nontraumatic cervical myelopathy or myeloradiculopathy (CMR). To analyze the related factors, C5P-LF and non-C5P-LF groups were compared. To assess the clinical parameters, preoperative diagnosis, clinical symptoms, surgical procedures, and outcome instruments were analyzed. Radiographically, we analyzed preoperative maximal spinal cord compression ratio, presence of C4-5 foraminal stenosis (FS), and correction angles on the sagittal plane. To compare with C5P-LP, we analyzed the incidence, time of onset, grade of muscle weakness, other accompanying cervical nerve root palsies, recovery time, and degree of final recovery in the C5P-LF and the C5P-LP groups of 100 consecutive LPs.

RESULTS

A total of 90 LF patients were enrolled (M:F = 54:36, mean age 61.1 yr, mean follow-up 35 months). C5P occurred in 26 patients (28.9%), and 14 cases (53.8%) demonstrated other cervical nerve root palsies. Clinically significant differences were observed between the C5P-LF and non-C5P-LF groups with regard to preoperative clinical diagnosis (CMR 88.5:42.2%, P < 0.001) and presence of preoperative upper extremity weakness (57.7:32.3%, P = 0.02). Comparison between the C5P-LF and C5P-LP groups showed significant differences between incidence (28.9:4%), mean grade of weakness (2.1:3.5), accompanying nerve root symptoms (53.8:0%), recovery time (20.8:10.5 weeks), and incidence of incomplete recovery (15.4:0%).

CONCLUSION

C5P-LF patients showed higher incidence, more severe weakness, frequent involvement of multiple cervical nerve roots, and longer recovery time than C5P-LP patients. Preoperative clinical manifestation of CMR and preexisting upper extremity weakness were the related factors of C5 palsy.

LEVEL OF EVIDENCE

3.

Comparison of anterior approach versus posterior approach for the treatment of multilevel cervical spondylotic myelopathy

PURPOSE

The purpose of this study is to evaluate the clinical outcomes, complications, and surgical trauma between anterior and posterior approaches for the treatment of multilevel cervical spondylotic myelopathy (CSM).

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

Randomized controlled trials or non-randomized controlled trials published up to November 2014 that compared the clinical effectiveness of anterior and posterior surgical approaches for the treatment of multilevel CSM were acquired by a comprehensive search in four electronic databases (PubMed, EMBASE, Cochrane Controlled Trial Register and MEDLINE). Exclusion criteria were non-controlled studies, combined anterior and posterior surgery and cervical myelopathy caused by ossification of the posterior longitudinal ligament. The main end points included: recovery rate; Japanese Orthopedic Association (JOA) score; complication rate; reoperation rate; blood loss; operation time and length of stay.

RESULTS

A total of ten studies were included in the meta-analysis; none of which were randomized controlled trials. All of the selected studies were of high quality as indicated by the Newcastle-Ottawa scale. In six studies involving 467 patients, there was no significant difference in the preoperative JOA score between the anterior surgery group and the posterior group [P > 0.05, WMD -0.00 (-0.50, 0.50)]. In four studies involving 268 patients, the postoperative JOA score was significantly higher in the anterior surgery group compared with the posterior surgery group [P < 0.05, WMD 0.79 (0.16, 1.42)]. In five studies involving 420 patients, there was no statistically significant difference in recovery rate between the anterior and posterior surgery groups [P > 0.05, WMD 2.73 (-8.69, 14.15)]. In nine studies involving 804 patients, the postoperative complication rate was significantly higher in the anterior surgery group compared with the posterior surgery group [P = 0.009, OR 1.65 (1.13, 2.39)]. In five studies involving 294 patients, the reoperation rate was significantly higher in the anterior surgery group compared with the posterior surgery group [P = 0.0001, OR 8.67 (2.85, 26.34)]. In the four studies involving 252 patients, the intraoperative blood loss and operation time was significantly higher in the anterior surgery group compared with the posterior surgery group [P < 0.05, WMD -40.25 (-76.96, -3.53) and P < 0.00001, WMD 61.3 (52.33, 70.28)]. In the three studies involving 192 patients, the length of stay was significantly lower in the anterior surgery group compared with the posterior surgery group [P < 0.00001, WMD -1.07 (-2.23, -1.17)].

CONCLUSIONS

In summary, our meta-analysis suggested that a definitive conclusion could not be reached regarding which surgical approach is more effective for the treatment of multilevel CSM. Although anterior approach was associated with better postoperative neural function than posterior approach in the treatment of multilevel CSM, there was no apparent difference in the neural function recovery rate between the two approaches. Higher rates of surgery-related complication and reoperation should be taken into consideration when anterior approach is used for patients with multilevel CSM.

Cervical laminoplasty developments and trends, 2003-2013: a systematic review

OBJECT

Despite extensive clinical experience with laminoplasty, the efficacy of the procedure and its advantages over laminectomy remain unclear. Specific clinical elements, such as incidence or progression of kyphosis, incidence of axial neck pain, postoperative cervical range of motion, and incidence of postoperative C-5 palsies, are of concern. The authors sought to comprehensively review the laminoplasty literature over the past 10 years while focusing on these clinical elements.

METHODS

The authors conducted a literature search of articles in the Medline database published between 2003 and 2013, in which the terms "laminoplasty," "laminectomy," and "posterior cervical spine procedures" were used as key words. Included was every single case series in which patient outcomes after a laminoplasty procedure were reported. Excluded were studies that did not report on at least one of the above-mentioned items.

RESULTS

A total of 103 studies, the results of which contained at least 1 of the prespecified outcome variables, were identified. These studies reported 130 patient groups comprising 8949 patients. There were 3 prospective randomized studies, 1 prospective nonrandomized alternating study, 15 prospective nonrandomized data collections, and 84 retrospective reviews. The review revealed a trend for the use of miniplates or hydroxyapatite spacers on the open side in Hirabayashi-type laminoplasty or on the open side in a Kurokawa-type laminoplasty. Japanese Orthopaedic Association (JOA) scoring was reported most commonly; in the 4949 patients for whom a JOA score was reported, there was improvement from a mean (± SD) score of 9.91 (± 1.65) to a score of 13.68 (± 1.05) after a mean follow-up of 44.18 months (± 35.1 months). The mean preoperative and postoperative C2-7 angles (available for 2470 patients) remained stable from 14.17° (± 0.19°) to 13.98° (± 0.19°) of lordosis (average follow-up 39 months). The authors found significantly decreased kyphosis when muscle/posterior element-sparing techniques were used (p = 0.02). The use of hardware in the form of hydroxyapatite spacers or miniplates did not influence the progression of deformity (p = 0.889). An overall mean (calculated from 2390 patients) of 47.3% loss of range of motion was reported. For the studies that used a visual analog scale score (totaling 986 patients), the mean (cohort size-adjusted) postoperative pain level at a mean follow-up of 29 months was 2.78. For the studies that used percentages of patients who complained of postoperative axial neck pain (totaling 1249 patients), the mean patient number-adjusted percentage was 30% at a mean follow-up of 51 months. The authors found that 16% of the studies that were published in the last 10 years reported a C-5 palsy rate of more than 10% (534 patients), 41% of the studies reported a rate of 5%-10% (n = 1006), 23% of the studies reported a rate of 1%-5% (n = 857), and 12.5% reported a rate of 0% (n = 168).

CONCLUSIONS

Laminoplasty remains a valid option for decompression of the spinal cord. An understanding of the importance of the muscle-ligament complex, plus the introduction of hardware, has led to progress in this type of surgery. Reporting of outcome metrics remains variable, which makes comparisons among the techniques difficult.

Development of postoperative C5 palsy is associated with wider posterior decompressions: an analysis of 41 patients

BACKGROUND CONTEXT

C5 palsy is a postoperative complication, characterized by deltoid weakness. The pathogenesis of C5 palsy after laminoforaminotomies in patients with degenerative spinal disease is poorly understood. We hypothesize that the spinal cord fallback is associated with postoperative C5 palsy.

PURPOSE

We investigate radiographic parameters associated with the development of postoperative C5 palsy.

STUDY DESIGN/SETTING

This is a retrospective single-institutional clinical study.

PATIENT SAMPLE

The source population was all patients undergoing a C4-C5 posterior laminoforaminotomy plus instrumented fusion for the management of degenerative spinal disease at a single institution over a 7-year period. The study population was 41 patients who had both preoperative and postoperative imaging.

OUTCOME MEASURE

The outcome measure was postoperative C5 palsy, defined as transient motor decline of the deltoid function.

METHODS

Of those patients with both preoperative and postoperative radiographic studies, we measured cord position, Cobb angle, width of the C5 foramen, and width of the dura.

RESULTS

Nine patients with C5 palsy and 32 patients without C5 palsy fit the inclusion criteria for this study. In comparison with the non-C5 palsy group, the C5 palsy group had a statistically greater widening of the C5 foramen (p<.001), dural expansion (p<.001), and posterior cord shift (p<.001). Change in lordosis did not differ (p=.985). Lordotic correction was not correlated with the posterior cord shift in linear regression analysis (p=.67) or C5 palsy in univariate analysis (p=.627). Conversely, widening of the C5 foramen was correlated with greater cord displacement (p=.002), and both of these factors statistically predicted C5 palsy after the multivariate regression analysis.

CONCLUSION

Our findings suggest that wider decompressions at C4-C5 are correlated with greater fallback of the spinal cord, which statistically increases the risk of C5 palsy.

Incidence and risk factors of C5 palsy following posterior cervical decompression: a systematic review

Background

C5 palsy is a serious but poorly understood complication after posterior cervical decompression that could lead to muscle weakness, brachialgia and numbness of the upper limbs. The incidence of C5 palsy varies greatly between studies. The risk factors are inconclusive and even conflicting.

Object

To perform a systematic review on the incidence and risk factors of C5 palsy after posterior cervical decompression.

Materials and Methods

Four databases, PubMed, Embase, Web of Science and Cochrane CENTRAL, were searched to identify eligible studies. Either a fixed- or a random-effects model was used to calculate the pooled odd ratio (RR) or standardized mean difference (SMD) with its 95% confidence interval (95%CI).

Results

Of the 589 pre-recruited studies, 25 were included in this study for systematic review. The pooled incidence of C5 palsy after posterior decompression was 5.8% (95%CI: 4.4–7.2%). The incidence after open-door laminoplasty, double-door laminoplasty and laminectomy was 4.5%, 3.1% and 11.3%, respectively. The significant risk factors of C5 palsy were OPLL (OR, 2.188; 95%CI, 1.307–3.665), narrower intervertebral foramen (SMD, −0.972; 95%CI, −1.398 to −0.545), laminectomy (vs. open-door laminoplasty, OR, 2.988; 95%CI, 1.298–6.876), excessive spinal cord drift (SMD, 1.289, 95%CI, 0,197–2.381) and male gender (OR, 1.54; 95%CI, 1.036–2.301).

Conclusions

The results of this systematic review suggest that patients with excessive spinal cord drift, preexisting intervertebral foramenal stenosis, OPLL, laminectomy and male gender are at high risk for postoperative C5 palsy, and risk-reduction options should be considered for such patients.

C5 nerve root palsy following decompression of the cervical spine

C5 nerve root palsy is a rare and potentially debilitating complication of cervical spine surgery. Currently, however, there are no guidelines to help surgeons to prevent or treat this complication.

We carried out a systematic review of the literature to identify the causes of this complication and options for its prevention and treatment. Searches of PubMed, Embase and Medline yielded 60 articles for inclusion, most of which addressed C5 palsy as a complication of surgery. Although many possible causes were given, most authors supported posterior migration of the spinal cord with tethering of the nerve root as being the most likely.

Early detection and prevention of a C5 nerve root palsy using neurophysiological monitoring and variations in surgical technique show promise by allowing surgeons to minimise or prevent the incidence of C5 palsy. Conservative treatment is the current treatment of choice; most patients make a full recovery within two years.

Cite this article: Bone Joint J 2014;96-B:950–5.

Computed tomographic evaluation of C5 root exit foramen in patients with cervical spondylotic myelopathy

BACKGROUND

Narrowing of the intervertebral foramen for C5 root and a larger superior articular process in myelopathic patients with postlaminoplasty motor dominant C5 radiculopathy has been reported. We investigated whether the C4-5 foraminal dimensions and surface area in patients with cervical spondylotic myelopathy are universally smaller than the intervertebral foramina at other cervical levels.

METHODS

The study population consisted of 44 consecutive patients (sex: 24 males and 20 females), averaging 55.7 years of age (range 42-84) years who presented with clinical features suggestive of cervical spondylotic myelopathy. Using computed tomography (CT) imaging, we prospectively compared height, transverse diameter, and surface area of the C4-5 foramen to those of C3-4, C5-6 and C6-7 foramina of the same side in the whole study population as well as in male and female patients.

RESULTS

In the whole study population at C4-5 intervertebral foramen the mean foraminal height was 8.37 ± 1.3 mm on the right and 8.85 ± 1.16 mm on the left; and the mean foraminal transverse diameter on the right was 4.97 ± 1.35 mm and 5.14 ± 1.16 mm on the left. No statistically significant difference was found between the measurements in the whole study population at various levels, between or within male and female patient groups.

CONCLUSION

C4-5 intervertebral foramen is not uniformly smaller in patients with cervical spondylotic myelopathy.

Two-year clinical and radiological outcomes of open-door cervical laminoplasty with prophylactic bilateral C4-C5 foraminotomy in a prospective study

STUDY DESIGN

A prospective study.

OBJECTIVE

To evaluate the 2-year outcomes of open-door cervical laminoplasty with prophylactic bilateral C4-C5 foraminotomy.

SUMMARY OF BACKGROUND DATA

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.

METHODS

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.

RESULTS

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).

CONCLUSION

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.

LEVEL OF EVIDENCE

3.