Extremely wide and asymmetric anterior decompression causes postoperative C5 palsy: an analysis of 32 patients with postoperative C5 palsy after anterior cervical decompression and fusion

Magnetic Resonance Imaging-CCCFLS Scoring System: Toward Predicting Clinical Symptoms and C5 Paralysis

STUDY DESIGN

A retrospective study.

OBJECTIVE

To develop a new MRI scoring system to assess patients' clinical characteristics, outcomes and complications.

METHODS

A retrospective 1-year follow-up study of 366 patients with cervical spondylosis from 2017 to 2021. The CCCFLS scores (cervical curvature and balance (CC), spinal cord curvature (SC), spinal cord compression ratio (CR), cerebrospinal fluid space (CFS). Spinal cord and lesion location (SL). Increased Signal Intensity (ISI) were divided into Mild group (0-6), Moderate group (6-12), and Severe group (12-18) for comparison, and the Japanese Orthopaedic Association (JOA) scores, visual analog scale (VAS), numerical rating scale (NRS), Neck Disability Index (NDI) and Nurick scores were evaluated. Correlation and regression analyses were performed between each variable and the total model in relation to clinical symptoms and C5 palsy.

RESULTS

The CCCFLS scoring system was linearly correlated with JOA, NRS, Nurick and NDI scores, with significant differences in JOA scores among patients with different CC, CR, CFS, ISI scores, with a predictive model (R2 = 69.3%), and significant differences in preoperative and final follow-up clinical scores among the 3 groups, with a higher rate of improvement in JOA in the severe group (P < .05), while patients with and without C5 paralysis had significant differences in preoperative SC and SL (P < .05).

CONCLUSION

CCCFLS scoring system can be divided into mild (0-6). moderate (6-12), severe (12-18) groups. It can effectively reflect the severity of clinical symptoms, and the improvement rate of JOA is better in the severe group, while the preoperative SC and SL scores are closely related to C5 palsy.

LEVEL OF EVIDENCE

III.

Unilateral biportal endoscopic decompression versus anterior cervical decompression and fusion for unilateral cervical radiculopathy or coexisting cervical myelopathy: a prospective, randomized, controlled, noninferiority trial

BACKGROUND

Cervical spondylosis (CS), including myelopathy and radiculopathy, is the most common degenerative cervical spine disease. This study aims to evaluate the clinical outcomes of unilateral biportal endoscopy (UBE) compared to those of conventional anterior cervical decompression and fusion (ACDF) for treating unilateral cervical radiculopathy or coexisting cervical myelopathy induced by unilateral cervical herniated discs.

METHODS

A prospective, randomized, controlled, noninferiority trial was conducted. The sample consisted of 131 patients who underwent UBE or ACDF was conducted between September 2021 and September 2022. Patients with cervical nerve roots or coexisting spinal cord compression symptoms and imaging-defined unilateral cervical radiculopathy or coexisting cervical myelopathy induced by unilateral cervical herniated discs were randomized into two groups: a UBE group (n = 63) and an ACDF group (n = 68). The operative time, blood loss, length of hospital stay after surgery, and perioperative complications were recorded. Preoperative and postoperative modified Japanese Orthopaedic Association (mJOA) scale scores, visual analog scale (VAS) scores, neck disability index (NDI) scores, and recovery rate (RR) of the mJOA were utilized to evaluate clinical outcomes.

RESULTS

The hospital stay after surgery was significantly shorter in patients treated with UBE than in those treated with ACDF (p < 0.05). There were no significant differences in the neck or arm VAS score, NDI score, mJOA score, or mean RR of the mJOA between the two groups (p < 0.05). Only mild complications were observed in both groups, with no significant difference (p = 0.30).

CONCLUSION

UBE can significantly relieve pain and disability without severe complications, and most patients are satisfied with this technique. Consequently, this procedure can be used safely and effectively as an alternative to ACDF for treating unilateral cervical radiculopathy or coexisting cervical myelopathy induced by unilateral cervical herniated discs.

TRIAL REGISTRATION

This study was registered in the Chinese Clinical Trial Registry on 02/08/2023 ( http://www.chictr.org.cn , #ChiCTR2300074273).

Characteristics of Postoperative C5 Palsy Following Anterior Decompression and Fusion Surgery for Cervical Degenerative Disorders: Trends Associated with Advancements in Surgical Technique

OBJECTIVE

To investigate trends in the characteristics of postoperative C5 palsy following anterior decompression and fusion associated with advancements in this surgical procedure to treat cervical degenerative disorders.

METHODS

We included 801 consecutive patients who underwent anterior decompression and fusion for cervical degenerative disorders from 2006 to 2019 and investigated the incidence, onset, and prognosis of C5 palsy. In addition, we compared the incidence of C5 palsy with that found in our previous investigation.

RESULTS

The cases of 42 (5.2%) patients were complicated by C5 palsy. For patients with ossification of the longitudinal ligament (OPLL), 22 (12.4%) of 177 were complicated with C5 palsy, and the incidence was significantly higher than that in patients without OPLL (20 [3.2%] of 624, P < 0.01). The incidence of C5 palsy in patients without OPLL was significantly lower than that found in our previous investigation (P < 0.01). The incidence of C5 palsy in patients that required contiguous multilevel corpectomy was significantly higher in patients that required within a single corpectomy (P < 0.01). At 1-year follow-up, muscle strength in 3 (6.1%) of 49 limbs had not improved sufficiently.

CONCLUSIONS

With advancements in surgical techniques which allowed necessary and sufficient spinal cord decompression and avoided unnecessary corpectomy, the incidence of C5 palsy in patients without OPLL was decreased significantly. By contrast, for patients with OPLL, the incidence of C5 palsy was similar to the incidence found previously, perhaps because a broad and contiguous multilevel corpectomy was usually needed to decompress the spinal cord sufficiently.

A Risk Calculator for the Prediction of C5 Nerve Root Palsy After Instrumented Cervical Fusion

BACKGROUND

C5 palsy is a common postoperative complication after cervical fusion and is associated with increased health care costs and diminished quality of life. Accurate prediction of C5 palsy may allow for appropriate preoperative counseling and risk stratification. We primarily aim to develop an algorithm for the prediction of C5 palsy after instrumented cervical fusion and identify novel features for risk prediction. Additionally, we aim to build a risk calculator to provide the risk of C5 palsy.

METHODS

We identified adult patients who underwent instrumented cervical fusion at a tertiary care medical center between 2013 and 2020. The primary outcome was postoperative C5 palsy. We developed ensemble machine learning, standard machine learning, and logistic regression models predicting the risk of C5 palsy-assessing discrimination and calibration. Additionally, a web-based risk calculator was built with the best-performing model.

RESULTS

A total of 1024 patients were included, with 52 cases of C5 palsy. The ensemble model was well-calibrated and demonstrated excellent discrimination with an area under the receiver-operating characteristic curve of 0.773. The following features were the most important for ensemble model performance: diabetes mellitus, bipolar disorder, C5 or C4 level, surgical approach, preoperative non-motor neurologic symptoms, degenerative disease, number of fused levels, and age.

CONCLUSIONS

We report a risk calculator that generates patient-specific C5 palsy risk after instrumented cervical fusion. Individualized risk prediction for patients may facilitate improved preoperative patient counseling and risk stratification as well as potential intraoperative mitigating measures. This tool may also aid in addressing potentially modifiable risk factors such as diabetes and obesity.

Morphology of cervical periradicular fibrous sheath and nerve roots in relation to postoperative C5 palsy

BACKGROUND CONTEXT

C5 palsy is a major complication of cervical spine surgery, however, its exact pathogenesis remains unclear. Some studies have shown that the superficial layer of the posterior longitudinal ligament extends laterally and forms the periradicular fibrous sheath (PFS), and envelopes the nerve roots. However, the anatomical relationship between the PFS and nerve root at each cervical level has not been fully revealed.

PURPOSE

To examine the difference of the PFS that covers the nerve root at each cervical level, and to consider its potential in the onset of postoperative C5 palsy.

STUDY DESIGN

Anatomical study of cervical dissection of 13 embalmed cadavers.

METHODS

Thirteen human formalin-fixed cadavers were dissected from posterior approach, and were observed their cervical nerves bilaterally from C3 to C8 (the total number of nerves was 156). The bare area length (BAL), which is the distance between the medial posterior edge of the PFS and the bifurcation of the nerve and dura mater, was measured by using electronic calipers. Thus, BAL is the uncovered area of the nerve root by the PFS. We examined whether BAL significantly varied at each cervical level.

RESULTS

We confirmed the PFS macro- and/or microanatomically in all cadavers. The average BAL gradually increased craniocaudally, and there was a significant step between that of C5 and C6 level.

CONCLUSION

The average BAL of the C5 root was significantly shorter than that of C6, C7, and C8, suggesting that C5 root was more tightly anchored. This could be one reason for C5 palsy, making C5 nerve root vulnerable to the traction caused by the postoperative spinal cord shift.

CLINICAL SIGNIFICANCE

This study provides clinicians an additional understanding of the anatomical factor of C5 palsy. Consideration of the anchoring effect of the PFS for nerve roots, release of the PFS could be a preventive procedure for C5 palsy.

Insufficient Recovery From C5 Palsy Following Anterior Cervical Decompression and Fusion

STUDY DESIGN

Retrospective study.

OBJECTIVE

To determine the risk factors for insufficient recovery from C5 palsy (C5P) following anterior cervical decompression and fusion (ADF).

SUMMARY OF BACKGROUND DATA

Postoperative C5P is a frequent but unsolved complication following cervical decompression surgery. Although most patients gradually recover, some recover only partially. When we encounter new-onset C5P following ADF, the question that often arises is whether the palsy will sufficiently resolve.

METHODS

We retrospectively reviewed consecutive patients who underwent ADF at our institution. We defined C5P as postoperative deterioration of deltoid muscle strength by two or more grades determined by manual muscle testing (MMT). We evaluated the following demographic data: patient factors, surgical factors, and radiological findings. C5P patients were divided into two groups: sufficient recovery (MMT grade≧4) and insufficient recovery (MMT grade < 4). Each parameter was compared between the two groups.

RESULTS

Of 839 patients initially included in the study, 57 experienced new-onset C5P (6.8%). At the final follow-up (mean, 55 ± 17 months), 41 patients experienced sufficient recovery, whereas 16 (28%) still exhibited insufficient recovery. Compared with the sufficient recovery group, patients with insufficient recovery exhibited a higher decompression combination score, a larger anterior shift in preoperative cervical sagittal balance, less lordosis of the pre- and postoperative C4/C5 segment, more frequent stenosis at the C3/C4 segment, lower deltoid strength at C5P onset, more frequent co-occurrence of biceps weakness, greater postoperative expansion of the dura mater, and more frequent presence of postoperative T2 high-intensity areas. Multivariate analysis revealed that co-occurrence of biceps muscle weakness, less lordosis at the preoperative C4/C5 segment, and postoperative expansion of the dura mater were independent predictors of insufficient recovery.

CONCLUSION

The combination of unfavorable conditions, such as potential spinal cord disorder, cervical malalignment, and excessive expansion of the dura mater after corpectomy, predicts insufficient recovery from C5P.Level of Evidence: 4.

Risk Factors and Prevention of C5 Palsy After Anterior Cervical Decompression and Fusion: Similarity of the Pathomechanism With That After a Posterior Approach

STUDY DESIGN

This was a retrospective study.

OBJECTIVE

The objective of this study was to review clinical and imaging findings after anterior cervical decompression and fusion, as a basis for prevention of C5 palsy.

SUMMARY OF BACKGROUND DATA

C5 palsy is a common postoperative complication in spine surgery, but the mechanistic basis for this condition is unknown.

MATERIALS AND METHODS

The subjects were 239 patients with cervical myelopathy who underwent anterior cervical decompression and fusion including at C4-C5 disk level at our hospital from 2001 to 2018. Twelve of these patients (5.0%) had C5 palsy postoperatively. Clinical features and imaging findings were compared in patients with and without C5 palsy.

RESULTS

In patients with C5 palsy, the sagittal alignment of the cervical spine was kyphotic, the width of the C5 intervertebral foramen was narrower, and the lateral decompressed line was wider beyond the medial part of the Luschka joint. Age, sex, disease, the number of fused segments, decompression width, and anterior shift of the spinal cord did not differ significantly between patients with and without C5 palsy.

CONCLUSIONS

These results indicate that the pathomechanism of C5 palsy may be dependent on the location of the lateral decompression line, especially in patients with cervical kyphosis and a narrow C5 intervertebral foramen. Excessive lateral decompression beyond the Luchka joint might lead to C5 root kinking between the intervertebral foramen and posterior edge of vertebra. This pathomechanism may be similar in anterior and posterior approaches. To prevent C5 palsy, the medial line of the Luschka joint should be confirmed intraoperatively and decompression should be performed within the Luschka joints. Alternatively, medial foraminotomy should be used in cases needing wide decompression, such as those with massive ossification of the posterior longitudinal ligament, lateral osteophytes, and symptomatic foraminal stenosis.

LEVEL OF EVIDENCE

Level III.

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.

Anterior Controllable Antedisplacement and Fusion (ACAF) Technique for the Treatment of Multilevel Cervical Spondylotic Myelopathy With Spinal Stenosis (MCSMSS): A Retrospective Study of 54 Cases

STUDY DESIGN

Retrospective study.

OBJECTIVE

To investigate the clinical effect of anterior controllable antedisplacement and fusion (ACAF) technique for the treatment of multilevel cervical spondylotic myelopathy with spinal stenosis (MCSMSS), compared with hybrid decompression fixation (HDF).

SUMMARY OF BACKGROUND DATA

A retrospective analysis of 94 cases with MCSMSS was carried out. Fifty-four patients were treated with ACAF, whereas 40 patients were treated with HDF.

METHODS

The operation time, intraoperative blood loss, postoperative complications, Japanese Orthopedic Association score, Neck Disability Index score, parameters at axial computed tomography, cervical curvature and the Kang grade were compared between 2 groups.

RESULTS

The patients were followed up for 12-17 (15.6±1.6) months. Compared with HDF, ACAF group achieved better decompression according to computed tomography measurement and Kang grade (P<0.05), and recovered to a greater cervical Cobb angle (P<0.05). However, Japanese Orthopedic Association score and Neck Disability Index showed no significant difference 1 year after surgery (P>0.05). In addition, ACAF presented longer operation time (P<0.05) and similar intraoperative blood loss (P>0.05), compared with HDF. In terms of complications, ACAF produced less incidences of cerebrospinal fluid leakage, implant complication, epidural hematoma, and C5 palsy compared with HDF.

CONCLUSIONS

ACAF is an effective method for the treatment of MCSMSS. In comparison to HDF, ACAF has the advantages of more sufficient decompression, more satisfactory cervical curvature, and lower incidence rates of complications.

Radiographic Measures of Spinal Alignment Are Not Predictive of the Development of C5 Palsy Following Anterior Cervical Discectomy and Fusion Surgery

BACKGROUND

Postoperative C5 palsy is a common complication following cervical decompression, occurring more frequently after posterior-based procedures. It has been theorized that this is the result of C5 nerve stretch resulting from spinal cord drift with these procedures. As such, it is thought to be less common after anterior cervical decompression and fusion (ACDF). However, no consensus has been reached on its true etiology. The purpose of this study is to assess the rate of C5 palsy following ACDF and to determine whether any radiographic or demographic parameters were predictive of its development.

METHODS

Two hundred and twenty-six patients who received ACDF between September 2015 and September 2016 were reviewed, and 122 were included in the final analysis. Patient demographic, surgical, and radiographic data were analyzed, including preoperative and postoperative radiographic and motor examination results. The Mann-Whitney U test was used to compare continuous variables between independent groups, and Fisher's exact test was used to compare categorical variables between groups.

RESULTS

Seven patients developed a C5 palsy in the postoperative period, an incidence rate of 5.7%. Among the radiographic parameters evaluated, there were no statistically significant differences between the C5 palsy and nonpalsy groups. Additionally, there were no statistically significant differences in age, patient sex, or numbers of vertebral levels fused between groups.

CONCLUSIONS

Ultimately, we did not identify any statistically significant demographic or radiographic predictive factors for the development of C5 palsy following ACDF surgery.

LEVEL OF EVIDENCE

3.

Patterns of neurological deficits and recovery of postoperative C5 nerve palsy

OBJECTIVE

Paresis of the C5 nerve is a well-recognized complication of cervical spine surgery. Numerous studies have investigated its incidence and possible causes, but the specific pattern and character of neurological deficits, time course, and relationship to preoperative cord signal changes remain incompletely understood.

METHODS

Records of patients undergoing cervical decompressive surgery for spondylosis, disc herniation, or ossification of the longitudinal ligament, including the C4-5 level, were reviewed from a 15-year period, identifying C5 palsy cases. Data collected included age, sex, diabetes and smoking statuses, body mass index, surgical levels, approach, presence of increased cord signal intensity, and modified Japanese Orthopaedic Association (mJOA) scores. Narrative descriptions of the patterns and findings on neurological examination were reviewed, and complications were noted. The minimum follow-up requirement for the study was 12 months.

RESULTS

Of 642 patients who underwent cervical decompressive surgery, 18 developed C5 palsy (2.8%). The incidence was significantly lower following anterior surgery (6 of 441 [1.4%]) compared with that following cervical laminectomy and fusion (12 of 201 [6.0%]) (p < 0.001). There were 10 men and 8 women whose mean age was 66.7 years (range 54-76 years). The mean preoperative mJOA score of 11.4 improved to 15.6 at the latest follow-up examination. There were no differences between those with and without C5 palsy with regard to sex, age, number of levels treated, or pre- or postoperative mJOA score. Fifteen patients with palsy (83%) had signal changes/myelomalacia on preoperative T2-weighted imaging, compared with 436 of 624 (70%) patients without palsy; however, looking specifically at the C4-5 level, signal change/myelomalacia was present in 12 of 18 (67%) patients with C5 palsy, significantly higher than in the 149 of 624 (24%) patients without palsy (p < 0.00003). Paresis was unilateral in 16 (89%) and bilateral in 2 (11%) patients. All had deltoid weakness, but 15 (83%) exhibited new biceps weakness, 8 (44%) had triceps weakness, and 2 (11%) had hand intrinsic muscle weakness. The mean time until onset of palsy was 4.6 days (range 2-14 days). Two patients (11%) complained of shoulder pain preceding weakness; 3 patients (17%) had sensory loss. Recovery to grade 4/5 deltoid strength occurred in 89% of the patients. No patient had intraoperative loss of somatosensory or motor evoked potentials or abnormal intraoperative C5 electromyography activity.

CONCLUSIONS

Postoperative C5 nerve root dysfunction appears in a delayed fashion, is predominantly a motor deficit, and weakness is frequently appreciated in the biceps and triceps muscles in addition to the deltoid muscle. Preoperative cord signal change/myelomalacia at C4-5 was a significant risk factor. No patient had a detectable deficit in the immediate postoperative period or changes in intraoperative neuromonitoring status. Neurological recovery to at least that of grade 4/5 occurred in nearly 90% of the patients.

Foraminal Ligaments Tether Upper Cervical Nerve Roots: A Potential Cause of Postoperative C5 Palsy

Background  Nerve root tethering upon dorsal spinal cord (SC) migration has been proposed as a potential mechanism for postoperative C5 palsy (C5P). To our knowledge, this is the first study to investigate this relationship by anatomically comparing C5–C6 nerve root translation before and after root untethering by cutting the cervical foraminal ligaments (FL).

Objective  The aim of this study is to determine if C5 root untethering through FL cutting results in increased root translation.

Methods  Six cadaveric dissections were performed. Nerve roots were exposed via C4–C6 corpectomies and supraclavicular brachial plexus exposure. Pins were inserted into the C5–C6 roots and adjacent foraminal tubercle. Translation was measured as the distance between pins after the SC was dorsally displaced 5 mm before and after FL cutting. Clinical feasibility of FL release was examined by comparing root translation between standard and extended (complete foraminal decompression) foraminotomies. Translation of root levels before and after FL cutting was compared by two-way repeated measures analysis of variance. Statistical significance was set at 0.05.

Results  Significantly more nerve root translation was observed if the FL was cut versus not-cut, p  = 0.001; no difference was seen between levels, p  = 0.33. Performing an extended cervical foraminotomy was technically feasible allowing complete FL release and root untethering, whereas a standard foraminotomy did not.

Conclusion  FL tether upper cervical nerve roots in their foramina; cutting these ligaments untethers the root and increases translation suggesting they could be harmful in the context of C5P. Further investigation is required examining the value of root untethering in the context of C5P.

Complications of anterior cervical spine surgery: a systematic review of the literature

The anterior approach to the cervical spine is commonly utilized for a variety of degenerative, traumatic, neoplastic, and infectious indications. While many potential complications overlap with those of the posterior approach, the distinct anatomy of the anterior neck also presents a unique set of hazards. We performed a systematic review of the literature to assess the etiology, presentation, natural history, and management of these complications. Following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), a PubMed search was conducted to evaluate clinical studies and case reports of patients who suffered a complication of anterior cervical spine surgery. The search specifically included articles concerning adult human subjects, written in the English language, and published from 1989 to 2019. The PubMed search yielded 240 articles meeting our criteria. The overall rates of complications were as follows: dysphagia 5.3%, esophageal perforation 0.2%, recurrent laryngeal nerve palsy 1.3%, infection 1.2%, adjacent segment disease 8.1%, pseudarthrosis 2.0%, graft or hardware failure 2.1%, cerebrospinal fluid leak 0.5%, hematoma 1.0%, Horner syndrome 0.4%, C5 palsy 3.0%, vertebral artery injury 0.4%, and new or worsening neurological deficit 0.5%. Morbidity rates in anterior cervical spine surgery are low. Nevertheless, the unique anatomy of the anterior neck presents a wide variety of potential complications involving vascular, aerodigestive, neural, and osseous structures.

Epidemiology of C5 Palsy after Cervical Spine Surgery: A 21-Center Study

Objective

C5 palsy is a severe complication after cervical spine surgery, the pathophysiology of which remains unclear. This multicenter study investigated the incidence of C5 palsy following cervical spine surgery in Korea.

Methods

We conducted a retrospective multicenter study involving 21 centers from the Korean Cervical Spine Study Group. The inclusion criteria were cervical spine surgery patients between 2012 and 2016, excluding cases of neck surgery. In patients with C5 palsy, the operative methods, disease category, onset time of C5 palsy, recovery time, C5 manual muscle testing (MMT) grade, and post-C5 palsy management were analyzed.

Results

We collected 15,097 cervical spine surgery cases from 21 centers. C5 palsy occurred in 88 cases (0.58%). C5 palsy was more common in male patients (p=0.019) and after posterior approach procedures (p<0.001). C5 palsy usually occurred within 3 days after surgery (77 of 88, 87.5%) and most C5 palsy patients recovered within 6 months (51 of 88, 57.95%). Thirty C5 palsy patients (34.09%) had motor weakness, with an MMT grade≤2. Only four C5 palsy patients (4.5%) did not recover during follow-up. Posterior cervical foraminotomy was performed in 7 cases (7.95%), and steroids were used in 56 cases (63.63%). Twenty-six cases (29.55%) underwent close observation only.

Conclusion

The overall incidence of C5 palsy was relatively low (0.58%). C5 palsy was more common after posterior cervical surgery and in male patients. C5 palsy usually developed within 3 days after surgery, and more than half of patients with C5 palsy recovered within 6 months.

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.

Potential Mechanism for Some Postoperative C5 Palsies: An Anatomical Study

STUDY DESIGN

Anatomical Study.

OBJECTIVE

Determine if shoulder depression (eg, taping the shoulders) might result in C5 nerve traction and subsequent injury.

SUMMARY OF BACKGROUND DATA

Postoperative C5 nerve palsy is a recognized entity that is still often enigmatic. Inferior shoulder depression is usually employed to assist with surgical visualization during cervical spine procedures.

METHODS

In the supine position, 10 adult fresh frozen human cadavers underwent dissection of the spinal cord and its adjacent dorsal, ventral roots, and spinal nerves from C4 to T1. In the supine position, the head was rotated ipsilaterally, contralaterally, and in lateral flexion. The shoulder was elevated, retracted, protracted, and depressed all with direct observation of nerve roots, intradural ventral/dorsal rootlets, or the spinal cord. The effects of these movements upon the cervical nerve rootlets were measured.

RESULTS

The greatest displacement of nervous tissue was generated by shoulder depression and occurred primarily at the intradural rootlet level. The nerve rootlets that underwent the greatest average displacement were found at C5, with a decreasing gradient to C7 and no gross motion at C8 or T1. With maximal shoulder depression, C5-C7 rootlet tension produced cord movement to the ipsilateral side, touching the dura mater covering the lateral vertebral column with the C5 nerve root moving farthest.

CONCLUSION

Shoulder depression is often used during cervical spine surgery. In cadavers, shoulder depression causes significant tension and displacement of the C5 nerve rootlets, and in the extreme, cord displacement to the ipsilateral side. This could be a mechanism for injury, putting patients at greater risk for postoperative C5 palsy.

LEVEL OF EVIDENCE

5.

Impact of the surgical strategy on the incidence of C5 nerve root palsy in decompressive cervical surgery

Objective

Our aim was to identify the impact of different surgical strategies on the incidence of C5 palsy.

Background

Degenerative cervical spinal stenosis is a steadily increasing morbidity in the ageing population. Postoperative C5 nerve root palsy is a common complication with severe impact on the patients´ quality of life.

Methods

We identified 1708 consecutive patients who underwent cervical decompression surgery due to degenerative changes. The incidence of C5 palsy and surgical parameters including type and level of surgery were recorded to identify predictors for C5 nerve palsy.

Results

The overall C5 palsy rate was 4.8%, with 18.3% of cases being bilateral. For ACDF alone the palsy rate was low (1.13%), compared to 14.0% of C5 palsy rate after corpectomy. The risk increased with extension of the procedures. Hybrid constructs with corpectomy plus ACDF at C3-6 showed significantly lower rates of C5 palsy (10.7%) than corpectomy of two vertebrae (p = 0.005). Multiple regression analysis identified corpectomy of C4 or C5 as a significant predictor. We observed a lower overall incidence for ventral (4.3%) compared to dorsal (10.9%) approaches (p<0.001). When imaging detected a postoperative shift of the spinal cord at index segment C4/5, palsy rate increased significantly (33.3% vs. 12.5%, p = 0.034).

Conclusions

Extended surgical strategies, such as dorsal laminectomies, multilevel corpectomies and procedures with extensive spinal cord shift were shown to display a high risk of C5 palsy. The use of extended procedures should therefore be employed cautiously. Switching to combined surgical methods like ACDF plus corpectomy can reduce the rate of C5 palsy.

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.

C5 palsy after insertion of a winged expandable cervical cage: a case report and literature review

C5 nerve root palsy is a well-known complication after anterior or posterior cervical decompression. Many theories have been proposed but the etiology is still unclear. The use of a winged expandable cage after single or multiple corpectomy is among the used techniques in reconstructing the cervical spine. Herein we report a case of C5 palsy after a three-level corpectomy and reconstruction using this device for the treatment of cervical spondylosis. In our case the preexisting foraminal stenosis, wide anterior decompression and partial improvement of cervical alignment were factors supposed contributing to the 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.

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.

Degenerative cervical myelopathy

Cervical myelopathy is the most common cause of acquired spinal cord compromise. The concept of degenerative cervical myelopathy (DCM), defined as symptomatic myelopathy associated with degenerative arthropathic changes in the spine axis, is being introduced. Given its progressive nature, treatment options have to be chosen in a timely manner. Surgical options include anterior discectomy and fusion (ACDF), anterior corpectomy and fusion (ACCF), arthroplasty (in highly select cases), posterior laminectomy with/without fusion, and laminoplasty. Indications for each should be carefully considered in individual patients. Riluzole, a sodium-glutamate antagonist, is a promising option to optimize neurologic outcomes post-surgery and is being examined in the CSM-Protect Randomized Controlled Trial. Preoperative risk assessment is mandatory for prognostication. Sagittal alignment is known to play an important role to optimize surgical outcome. Guidelines for optimal management of DCM are in process. In principle, all but the mildest cases of DCM should be offered surgery for optimal outcome.

Postoperative Delayed Cervical Palsies: Understanding the Etiology

STUDY DESIGN

Retrospective study.

OBJECTIVE

This study reviews 1,768 consecutive cervical decompressions with or without instrumented fusion to identify patient-specific and procedural risk factors significantly correlated with the development of delayed cervical palsy (DCP).

METHODS

Baseline demographic and procedural information was collected from the electronic medical record. Particular attention was devoted to reviewing each chart for recognized risk factors of postsurgical inflammatory neuropathy: autoimmune disease, blood transfusions, diabetes, and smoking.

RESULTS

Of 1,669 patients, 56 (3.4%) developed a DCP. Although 71% of the palsies involved C5, 55% of palsies were multimyotomal and 18% were bilateral. Significant risk factors on univariate analysis included age (p = 0.0061, odds ratio [OR] = 1.07, 95% confidence interval [CI] 1.008 to 1.050), posterior instrumented fusion (p < 0.0001, OR = 3.30, 95% CI 1.920 to 5.653), prone versus semisitting/sitting position (p = 0.0036, OR = 3.58, 95% CI 1.451 to 11.881), number of operative levels (p < 0.0001, OR = 1.42, 95% CI 1.247 to 1.605), intraoperative transfusions (p = 0.0231, OR = 2.57, 95% CI 1.152 to 5.132), and nonspecific autoimmune disease (p = 0.0107, OR = 3.83, 95% CI 1.418 to 8.730). On multivariate analysis, number of operative levels (p = 0.0053, OR = 1.27, 95% CI 1.075 to 1.496) and nonspecific autoimmune disease (p = 0.0416, OR 2.95, 95% CI 1.047 to 7.092) remained significant.

CONCLUSIONS

Although this study partially supports a mechanical etiology in the pathogenesis of a DCP, we also describe a notable correlation with autoimmune risk factors. Bilateral and multimyotomal involvement provides additional support that some DCPs may result from an inflammatory response and thus an underlying multifactorial etiology for this complication.

Standalone Anterior Cervical Discectomy and Fusion Versus Combination with Foraminotomy for the Treatment of Cervical Spondylotic Radiculopathy Secondary to Bony Foraminal Stenosis

OBJECTIVE

To compare the results of anterior cervical discectomy and fusion (ACDF) combined with anterior cervical foraminotomy (ACF) and standalone ACDF for the treatment of cervical spondylotic radiculopathy (CSR).

METHODS

The data of 24 consecutive patients who underwent ACDF combined with ACF for significant bony foraminal stenosis were reviewed. The clinical outcomes, including visual analog scale (VAS) scores for neck pain and arm pain and Neck Disability Index, were evaluated by questionnaires. Radiologic outcomes as manifested by C2-7 angle and surgical segmental angle were recorded. The outcomes were compared with outcomes of standalone ACDF for CSR secondary to posterolateral spurs.

RESULTS

At the final follow-up evaluation, all patients obtained bone fusion. No patient developed adjacent segment disease. Operative time was longer and blood loss was more in the ACDF combined with ACF group than in the ACDF group (all P < 0.05). However, in both groups, the neck VAS score, arm VAS score, and Neck Disability Index were significantly reduced postoperatively (all P < 0.05). The segmental curve and C2-7 lordosis were significantly improved postoperatively (all P < 0.05). There was no significant difference between the 2 groups in clinical and radiologic outcomes (P > 0.05).

CONCLUSIONS

For CSR with foraminal stenosis secondary to significant bony pathology that cannot be managed with standalone ACDF, ACDF combined with ACF is an effective and safe treatment strategy.

Complications following central corpectomy in 468 consecutive patients with degenerative cervical spine disease

OBJECTIVE

This study was performed to describe the incidence and predictors of perioperative complications following central corpectomy (CC) in 468 consecutive patients with cervical spondylotic myelopathy (CSM) or ossification of the posterior longitudinal ligament (OPLL).

METHODS

The authors performed a retrospective review of a cohort of patients who had undergone surgery for CSM (n = 338) or OPLL (n = 130) performed by a single surgeon over a 15-year period. All patients underwent uninstrumented CC with autologous iliac crest or fibular strut grafting. Preoperative clinical and imaging details were collected, and the type and incidence of complications were studied. Univariate and multivariate analyses were performed to establish risk factors for the development of perioperative complications.

RESULTS

Overall, 12.4% of patients suffered at least 1 complication following CC. The incidence of major complications was as follows: C-5 radiculopathy, 1.3%; recurrent laryngeal nerve injury, 0.4%; dysphagia, 0.8%; surgical-site infection, 3.4%; and dural tear, 4.3%. There was 1 postoperative death (0.2%). On multivariate analysis, patients in whom the corpectomy involved the C-4 vertebral body (alone or as part of multilevel CC) were significantly more likely to suffer complications (p = 0.004). OPLL and skip corpectomy were risk factors for dural tear (p = 0.015 and p = 0.001, respectively). No factors were found to be significantly associated with postoperative C-5 palsy, dysphagia, or acute graft extrusion on univariate or multivariate analysis. Patients who underwent multilevel CC were predisposed to surgical-site infections, with a slight trend toward statistical significance (p = 0.094). The occurrence of a complication after surgery significantly increased the mean duration of postoperative hospital stay from 5.0 ± 2.3 days to 8.9 ± 6 days (p < 0.001).

CONCLUSIONS

Complications following CC for CSM or OPLL are infrequent, but they significantly prolong hospital stay. The most frequent complication following CC is dural tear, for which a diagnosis of OPLL and a skip corpectomy are significant risk factors.

C5 palsy and cervical laminectomy width: what is the right answer?

Klement MR, Kleeman LT, Blizzard DJ, Gallizzi MA, Eure M, Brown CR. C5 palsy after cervical laminectomy and fusion: does width of laminectomy matter? Spine J 2016:16:462-7 (in this issue).

C5 Nerve root palsies following cervical spine surgery: A review

Background:

Cervical C5 nerve root palsies may occur in between 0% and 30% of routine anterior or posterior cervical spine operations. They are largely attributed to traction injuries/increased cord migration following anterior/posterior decompressions. Of interest, almost all studies cite spontaneous resolution of these deficits without surgery with 3–24 postoperative months.

Methods:

Different studies cite various frequencies for C5 root palsies following anterior or posterior cervical spine surgery. In their combined anterior/posterior series involving C4-C5 level decompressions, Libelski et al. cited up to a 12% incidence of C5 palsies. In Gu et al. series, C5 root palsies occurred in 3.1% of double-door laminoplasty, 4.5% of open-door laminoplasty, and 11.3% of laminectomy. Miller et al. observed an intermediate 6.9% frequency of C5 palsies followed by posterior cervical decompressions and fusions (PCDF).

Results:

Gu et al. also identified multiple risk factors for developing C5 palsies following posterior surgery; male gender, ossification of the posterior longitudinal ligament (OPLL), narrower foramina, laminectomy, and marked dorsal spinal cord drift. Miller et al. also identified an average $1918 increased cost for physical/occupational therapy for patients with C5 palsies.

Conclusions:

The incidence of C5 root deficits for anterior/posterior cervical surgery at C4-C5 was 12% in one series, and ranged up to 11.3% for laminectomies, while others cited 0–30%. Although identification of preoperative risk factors for C5 root deficits may help educate patients regarding these risks, there is no clear method for their avoidance at this time.