Prevalence of C5 nerve root palsy after cervical decompressive surgery: a meta-analysis

Upper Extremity Nerve Transfers for Treatment of Nerve Injury After Cervical Spine Surgery: A Single-Center Retrospective Review

PURPOSE

Nerve transfers to restore or augment function after spinal cord injury is an expanding field. There is a paucity of information, however, on the use of nerve transfers for patients having undergone spine surgery. The incidence of neurologic deficit after spine surgery is rare but extremely debilitating. The purpose of this study was to describe the functional benefit after upper extremity nerve transfers in the setting of nerve injury after cervical spine surgery.

METHODS

A single-center retrospective review of all patients who underwent nerve transfers after cervical spine surgery was completed. Patient demographics, injury features, spine surgery procedure, nerve conduction and electromyography study results, time to referral to nerve surgeon, time to surgery, surgical technique and number of nerve transfers performed, complications, postoperative muscle testing, and subjective outcomes were reviewed.

RESULTS

Fourteen nerve transfers were performed in 6 patients after cervical spine surgery. Nerve transfer procedures consisted of a transfer between a median nerve branch of flexor digitorum superficialis into a biceps nerve branch, an ulnar nerve branch of flexor carpi ulnaris into a brachialis nerve branch, a radial nerve branch of triceps muscle into the axillary nerve, and the anterior interosseous nerve into the ulnar motor nerve. Average patient age was 55 years; all patients were male and underwent surgery on their left upper extremity. Average referral time was 7 months, average time to nerve transfer was 9 months, and average follow-up was 21 months. Average preoperative muscle grading was 0.9 of 5, and average postoperative muscle grading was 4.1 of 5 ( P < 0.00001).

CONCLUSIONS

Upper extremity peripheral nerve transfers can significantly help patients regain muscle function from deficits secondary to cervical spine procedures. The morbidity of the nerve transfers is minimal with measurable improvements in muscle function.

Comparison of Anterior Cervical Decompression and Fusion and Posterior Laminoplasty for Four-Segment Cervical Spondylotic Myelopathy: Clinical and Radiographic Outcomes

BACKGROUND

 Although anterior or posterior surgery for cervical spondylotic myelopathy (CSM) has been extensively studied, the choice of anterior or posterior approach in four-segment CSM remains poorly studied and controversial. We compared the clinical and radiographic outcomes of four-segment CSM by posterior laminoplasty (LAMP) and anterior cervical decompression fusion (ACDF) to further explore the merits and demerits of ACDF and LAMP for four-segment CSM in this study.

METHODS

 Patients with four-segment CSM who underwent ACDF or LAMP between January 2016 and June 2019 were retrospectively analyzed. We compared the preoperative and postoperative cervical Japanese Orthopaedic Association (JOA) scores, neck disability index (NDI), neck pain visual analog scale (VAS) score, sagittal vertical axis, cervical lordosis (CL), and range of motion.

RESULTS

 There were 47 and 79 patients in the ACDF and LAMP groups, respectively. Patients in the ACDF group had a significantly longer surgical time and lower estimated blood loss and length of stay than those in the LAMP group. There was no significant difference in the JOA, NDI, or neck pain VAS scores between the two groups preoperatively, but the NDI and neck pain VAS scores in the ACDF group were significantly lower than those in the LAMP group at the final follow-up. The preoperative C2-C7 Cobb angle of the ACDF group was significantly lower than that of the LAMP group but there was no significant difference between the two groups postoperatively. The improvement of C2-C7 Cobb angle (∆C2-C7 Cobb angle) in the ACDF group was significantly higher than that in the LAMP group. This indicated that ACDF can improve CL better than LAMP. The linear regression analysis revealed the ∆C2-C7 Cobb angle was negatively correlated with the final follow-up neck pain VAS scores and NDI. This indicated that patients with better improvement of CL may have a better prognosis.

CONCLUSIONS

 Although both ACDF and LAMP surgeries are effective for four-segment CSM, ACDF can better improve CL and neck pain. For patients with poor CL, we suggest ACDF when both approaches are feasible.

C5 palsy following esophageal diverticulum resection

Background

C5 palsy (C5P) is a recognized potential postoperative complication of cervical spine surgery but has rarely been reported following an open esophageal diverticulectomy.

Methods

A 61-year-old underwent an open esophageal diverticulectomy for symptomatic Zencker's diverticulum.

Results

Postoperatively, she presented with right upper extremity weakness and sensory deficits consistent with a C5P that was later confirmed by electromyography.

Conclusion

The potential for C5P after esophageal diverticulectomy for symptomatic Zencker's diverticulum is rare. Postoperative recognition and appropriate management are critical to recovery.

Comparison of Postoperative Complications and Outcomes in Anterior Cervical Spine Surgery: Ossification of the Posterior Longitudinal Ligament Versus Cervical Spondylotic Myelopathy

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

To compare the frequency of complications and outcomes between patients with ossification of the posterior longitudinal ligament (OPLL) of the cervical spine and those with cervical spondylotic myelopathy (CSM) who underwent anterior surgery.

SUMMARY OF BACKGROUND DATA

Anterior cervical spine surgery for OPLL is an effective surgical procedure; however, it is complex and technically demanding compared with the procedure for CSM. Few reports have compared postoperative complications and clinical outcomes after anterior surgeries between the 2 pathologies.

METHODS

Among 1434 patients who underwent anterior cervical spine surgery at 3 spine centers within the same spine research group from January 2011 to March 2021, 333 patients with OPLL and 488 patients with CSM were retrospectively evaluated. Demographics, postoperative complications, and outcomes were reviewed by analyzing medical records. In-hospital and postdischarge postoperative complications were investigated. Postoperative outcomes were evaluated 1 year after the surgery using the Japanese Orthopaedic Association score.

RESULTS

Patients with OPLL had more comorbid diabetes mellitus preoperatively than patients with CSM ( P <0.001). Anterior cervical corpectomies were more often performed in patients with OPLL than in those with CSM (73.3% and 14.5%). In-hospital complications, such as reoperation, cerebrospinal fluid leak, C5 palsy, graft complications, hoarseness, and upper airway complications, occurred significantly more often in patients with OPLL. Complications after discharge, such as complications of the graft bone/cage and hoarseness, were significantly more common in patients with OPLL. The recovery rate of the Japanese Orthopaedic Association score 1 year postoperatively was similar between patients with OPLL and those with CSM.

CONCLUSION

The present study demonstrated that complications, both in-hospital and after discharge following anterior spine surgery, occurred more frequently in patients with OPLL than in those with CSM.

Comparison of radiological and clinical outcomes of cervical laminoplasty versus lateral mass screw fixation in patients with ossification of the posterior longitudinal ligament

PURPOSE

This study aimed to compare cervical sagittal parameters and clinical outcomes between patients undergoing cervical laminoplasty(CL) and those undergoing lateral mass screw fixation(LMS).

METHODS

We retrospectively studied 67 patients with multilevel ossification of the posterior longitudinal ligament (OPLL) of the cervical spine who underwent lateral mass screw fixation (LMS = 36) and cervical laminoplasty (CL = 31). We analyzed cervical sagittal parameters (C2-7 sagittal vertical axis (C2-7 SVA), C0-2 Cobb angle, C2-7 Cobb angle, C7 slope (C7s), T1 slope (T1s), and spino-cranial angle (SCA)) and clinical outcomes (visual analog scale [VAS], neck disability index [NDI], Japanese Orthopaedic Association [JOA] scores, recovery rate (RR), and minimum clinically significant difference [MCID]). The cervical sagittal parameters at the last follow-up were analyzed by binary logistic regression. Finally, we analyzed the correlation between the cervical sagittal parameters and each clinical outcome at the last follow-up after surgery in both groups.

RESULTS

At the follow-up after posterior decompression in both groups, the mean values of C2-C7 SVA, C7s, and T1s in the LMS group were more significant than those in the CL group (P ≤ 0.05). Compared with the preoperative period, C2-C7 SVA, T1s, and SCA gradually increased, and the C2-C7 Cobb angle gradually decreased after surgery (P < 0.05). The improvement in the JOA score and the recovery rate was similar between the two groups, while the improvement in the VAS-N score and NDI score was more significant in the CL group (P = 0.001; P = 0.043). More patients reached MCID in the CL group than in the LMS group (P = 0.036). Binary logistic regression analysis showed that SCA was independently associated with whether patients reached MCID at NDI postoperatively. SCA was positively correlated with cervical NDI and negatively correlated with cervical JOA score at postoperative follow-up in both groups (P < 0.05); C2-7 Cobb angle was negatively correlated with cervical JOA score at postoperative follow-up (P < 0.05).

CONCLUSION

CL may be superior to LMS in treating cervical spondylotic myelopathy caused by OPLL. In addition, smaller cervical SCA after posterior decompression may suggest better postoperative outcomes.

Deep learning-based prediction model for postoperative complications of cervical posterior longitudinal ligament ossification

PURPOSE

Postoperative complication prediction helps surgeons to inform and manage patient expectations. Deep learning, a model that finds patterns in large samples of data, outperform traditional statistical methods in making predictions. This study aimed to create a deep learning-based model (DLM) to predict postoperative complications in patients with cervical ossification of the posterior longitudinal ligament (OPLL).

METHODS

This prospective multicenter study was conducted by the 28 institutions, and 478 patients were included in the analysis. Deep learning was used to create two predictive models of the overall postoperative complications and neurological complications, one of the major complications. These models were constructed by learning the patient's preoperative background, clinical symptoms, surgical procedures, and imaging findings. These logistic regression models were also created, and these accuracies were compared with those of the DLM.

RESULTS

Overall complications were observed in 127 cases (26.6%). The accuracy of the DLM was 74.6 ± 3.7% for predicting the overall occurrence of complications, which was comparable to that of the logistic regression (74.1%). Neurological complications were observed in 48 cases (10.0%), and the accuracy of the DLM was 91.7 ± 3.5%, which was higher than that of the logistic regression (90.1%).

CONCLUSION

A new algorithm using deep learning was able to predict complications after cervical OPLL surgery. This model was well calibrated, with prediction accuracy comparable to that of regression models. The accuracy remained high even for predicting only neurological complications, for which the case number is limited compared to conventional statistical methods.

Trends in cervical laminoplasty and 30-day postoperative complications: 10-year results from a retrospective, multi-institutional study of 1095 patients

PURPOSE

This study aimed to investigate the recent 10-year trends in cervical laminoplasty and 30-day postoperative complications.

METHODS

This retrospective multi-institutional cohort study enrolled patients who underwent laminoplasty for cervical spondylotic myelopathy (CSM) or ossification of the posterior longitudinal ligament. The primary outcome was the occurrence of all-cause 30-day complications. Trends were investigated and compared in the early (2008-2012) and late (2013-2017) periods.

RESULTS

Among 1095 patients (mean age, 66 years; 762 [70%] male), 542 and 553 patients were treated in the early and late periods, respectively. In the late period, patients were older at surgery (65 years vs. 68 years), there were more males (66% vs. 73%), and open-door laminoplasty (50% vs. 69%) was the preferred procedure, while %CSM (77% vs. 78%) and the perioperative JOA scores were similar to the early period. During the study period, the rate of preservation of the posterior muscle-ligament complex attached to the C2/C7-spinous process (C2, 89% vs. 93%; C7, 62% vs. 85%) increased and the number of laminoplasty levels (3.7 vs. 3.1) decreased. While the 30-day complication rate remained stable (3.9% vs. 3.4%), C5 palsy tended to decrease (2.4% vs. 0.9%, P = 0.059); superficial SSI increased significantly (0% vs. 1.3%, P = 0.015), while the decreased incidence of deep SSI did not reach statistical significance (0.6% vs. 0.2%).

CONCLUSIONS

From 2008 to 2017, there were trends toward increasing age at surgery and surgeons' preference for refined open-door laminoplasty. The 30-day complication rate remained stable, but the C5 palsy rate halved.

Comparison of clinical efficacy between retention and removal of the vertebral bony endplate in anterior cervical discectomy and fusion for the treatment of cervical spondylotic myelopathy

BACKGROUND

Anterior cervical discectomy and fusion (ACDF) have a history of more than 60 years to treat cervical spondylotic myelopathy. This study is based on the original classic surgical procedure to remove the bony endplate to expand the range of vertical decompression to analyze and compare the clinical efficacy of two different ACDF in treating cervical spondylotic myelopathy.

METHODS

The inpatients in hospital were randomly divided into two groups A and B. Patients in Group A received ACDF surgery with bony endplates preserved, and patients in group B received ACDF surgery with bony endplates removed. All patients were followed-up for three years, and then compared the clinical efficacy from the following aspects, blood loss statistics during and after the operation, Japanese Orthopedic Association's scoring (JOA) standard for cervical spondylotic myelopathy, Cervical curvature index, cervical flexion and extension range, intervertebral bone graft fusion time and fusion rate.

RESULTS

1. The operative time and intraoperative (postoperative) blood loss in group A were significantly better than that in group B, with statistical significance (P < 0.05)0.2. There was no significant difference in postoperative neurological function recovery, cervical curvature index, cervical flexion and extension activity, and Intervertebral fusion time between two groups (P > 0.05), while group A was superior to group B in terms of bone graft fusion rate (P < 0.05). 3. Four patients (6.7%) in group B suffered from dyspnea due to neck hematoma caused by drainage tube blockage, but all of them were cured immediately and no death occurred.

CONCLUSIONS

During the 3-year follow-up period after the operation, six patients in group B have subsidence and loosening of the internal fixator due to bone subsidence around the implant. Although immediate surgical treatment is not required, renovation surgery is inevitable in the long term.

Design and mechanical properties of cervical fusion cage based on porous entangled metal rubber material

Titanium and its alloys are one of the mainstream materials for the manufacture of intervertebral cages. With the application on clinical, the problems of elastic modulus is relatively high, subsidence of adjacent vertebral implants and stress shielding after surgery have gradually exposed. In this paper, metal rubber made from titanium alloy wire was used to prepare cervical fusion cage (CFC), which was a porous material with buffering and vibration damping properties. The C5/C6 segment of the goat cervical vertebra was used as the research object. The shape parameters of the CFC were determined by combining the three-dimensional model data of the cervical vertebra and the structural characteristics of the natural intervertebral disc. The force of CFC under different working conditions were simulated and analyzed by finite element simulation. Then three kinds of metal rubber core (MRC) were prepared by medical titanium alloy wire (TC4), and their mechanical properties and fatigue strength were experimentally studied. With the increases of density, the mechanical properties of MRC improved. The variation range of the loss factor η under different amplitudes and frequencies were 20% and 16.3%, respectively. After one million vibrations, the wear rate was 0.131 g/MC; after five million vibrations, the wear rate was 0.158 g/MC, which was similar to the existing clinical prosthesis wear rate. The MRC has sufficient mechanical strength. Compared with the existing clinical prostheses, it has a longer service life and has broad application prospects.

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.

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.

Postoperative C5 Palsy Following Cervical Laminectomy With Instrumented Fusion Versus Cervical Laminoplasty With Reconstruction: Single Surgeon and National Inpatient Cohort Analyses

STUDY DESIGN

This was a retrospective cohort study.

OBJECTIVE

The objective of this study was to investigate whether cervical laminectomy with instrumented fusion (LF) and cervical laminoplasty with reconstruction (LP) are associated with different rates C5 palsy (C5P) at 1-month follow-up in a single surgeon and nationally representative cohort.

SUMMARY OF BACKGROUND DATA

LF and LP both carry a well-known risk of nerve root injury that most commonly presents as C5P which can reduce patient satisfaction, patient function, and impede patient recovery. The procedure type that is more frequently associated with C5P remains largely unclear.

METHODS

We identified patients undergoing primary LF or LP procedures for the treatment of cervical myelopathy in both a single-surgeon series cohort (2004-2018; Mount Sinai Hospital) and a nationally representative cohort drawn from the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database (2006-2017). For the single-surgeon cohort, C5P within 1 month of surgery was recorded. For the NSQIP cohort, peripheral nerve injury (PNI) within 1 month of surgery was recorded and used as a proxy for C5P. Postoperative complications including C5P were compared between cohorts. Multivariable logistic regression was used to evaluate the association between procedure type and postoperative C5P or PNI.

RESULTS

Without adjusting for covariates, LF patients had a higher rate of 1-month C5P in the single-surgeon cohort (8% vs. 0%, P=0.01). An adjusted odds ratio could not be obtained due to the absence of C5P in the LP group. In the national cohort, LP patients had a significantly higher rate of 1-month PNI on unadjusted analysis (11% vs. 16%, P<0.001). After adjusting for covariates, we found no significant difference in odds of 1-month PNI between LF and LP (adjusted odds ratio=0.84, P=0.07).

CONCLUSIONS

Overall, the single-surgeon series suggest that cervical LF is associated with significantly higher rates of postoperative C5P as compared with LP. These findings are not corroborated by nationally representative data, which showed no difference in PNI rates between LF and LP. A surgeon's training and experience likely contribute to which procedure has a higher propensity for a C5P as a complication. Regardless, both LF and LP patients should be closely monitored for new-onset C5P during follow-up visits.

LEVEL OF EVIDENCE

Level III.

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.

Efficacy and safety of anterior cervical discectomy and fusion (ACDF) through mini-incision and posterior laminoplasty (LAMP) for treatment of long-level cervical spondylosis: a retrospective cohort study

BACKGROUND

The efficacy and safety of anterior cervical discectomy and fusion (ACDF) through mini-incision and posterior laminoplasty for long-level cervical spondylosis were investigated.

METHOD

From January 2018 to September 2019, clinical patients data with 3-4 segments (C3-7) cervical spondylotic radiculopathy, cervical spondylotic myelopathy, or mixed cervical spondylosis who received ACDF (42 cases) throughwith mini-incision or LAMP (36 cases) treatment were retrospectively collected and analyzed. The operative time, bleeding volume, incisive length, and hospital stay were recorded. Moreover, the intervertebral height, functional segment height, cervical lordosis, cervical hyperextension and hyperflexion range-of-motion (ROM) and ROM in all directions of the cervical spine before and after the operation were measured. Additionally, all relevant postoperative complications were also recorded. Then, the therapeutic effects of both surgical methods were investigated.

RESULTS

Patients in the ACDF group had less bleeding, shorter incision, and fewer hospitalization days than the LAMP group. There was no significant difference in JOA, VAS score of the upper limb, NDI score after surgery between two groups. Postoperative intervertebral height and functional segment height in the ACDF group were significantly higher than those before the operation, and postoperative functional segment height of the ACDF group was significantly higher than that of the LAMP group. Moreover, the postoperative cervical lordosis angle in the ACDF group was significantly larger than the LAMP group. There was no significant difference between preoperative and postoperative ROM in all directions of the cervical spine for the two groups.

CONCLUSIONS

Both ACDF through mini-incision and LAMP are effective treatments for long-level cervical spondylosis. However, ACDF through mini-incision shows minor trauma, less bleeding, fast recovery, and it is beneficial for cervical lordosis reconstruction.

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.

Efficacy of Intraoperative Neuromonitoring Using Transcranial Motor-Evoked Potentials for Degenerative Cervical Myelopathy: A Prospective Multicenter Study by the Monitoring Committee of the Japanese Society for Spine Surgery and Related Research

STUDY DESIGN

A prospective multicenter observational study.

OBJECTIVE

To elucidate the efficacy of transcranial motor-evoked potentials (Tc(E)-MEPs) in degenerative cervical myelopathy (DCM) surgery by comparing cervical spondylotic myelopathy (CSM) to cervical ossification of the posterior longitudinal ligament (OPLL) and investigate the timing of Tc(E)-MEPs alerts and types of interventions affecting surgical outcomes.

SUMMARY OF BACKGROUND DATA

Although CSM and OPLL are the most commonly encountered diseases of DCM, the benefits of Tc(E)-MEPs for DCM remain unclear and comparisons of these two diseases have not yet been conducted.

METHODS

We examined the results of Tc(E)-MEPs from 1176 DCM cases (840 CSM /336 OPLL) and compared patients background by disease, preoperative motor deficits, and the type of surgical procedure. We also assessed the efficacy of interventions based on Tc(E)-MEPs alerts. Tc(E)-MEPs alerts were defined as an amplitude reduction of more than 70% below the control waveform. Rescue cases were defined as those in which waveform recovery was achieved after interventions in response to alerts and no postoperative paralysis.

RESULTS

Overall sensitivity was 57.1%, and sensitivity was higher with OPLL (71.4%) than with CSM (42.9%). The sensitivity of acute onset segmental palsy including C5 palsy was 40% (OPLL/CSM: 66.7%/0%) whereas that of lower limb palsy was 100%. The most common timing of Tc(E)-MEPs alerts was during decompression (63.16%), followed by screw insertion (15.79%). The overall rescue rate was 57.9% (OPLL/CSM: 58.3%/57.1%).

CONCLUSION

Since Tc(E)-MEPs are excellent for detecting long tract injuries, surgeons need to consider appropriate interventions in response to alerts. The detection of acute onset segmental palsy by Tc(E)-MEPs was partially possible with OPLL, but may still be difficult with CSM. The rescue rate was higher than 50% and appropriate interventions may have prevented postoperative neurological complications.Level of Evidence: 3.

Treatment of cervical myelopathy by posterior approach: Laminoplasty vs. laminectomy with posterior fixation, are there differences from a clinical and radiological point of view?

INTRODUCTION

Cervical degenerative myelopathy is a variable and progressive degenerative disease caused by chronic compression of the spinal cord. Surgical approaches for the cervical spine can be performed anteriorly and/or posteriorly. Regarding the posterior approach, there are 2 fundamental techniques: laminoplasty and laminectomy with posterior fixation (LPF). There is still controversy concerning the technique in terms of outcome and complications. The aim of the present work is to analyze from the clinical and radiological point of view these 2 techniques: laminoplasty and LPF.

MATERIALS AND METHODS

A historical cohort of 39 patients was reviewed (12 LFP and 27 laminoplasty) including patients operated in a 10 years period at the Hospital Universitario La Paz with a follow-up of 12 months after surgery was carried out. The clinical results were analyzed and compared using the Nurick scale and the modified Japanese Orthopaedic Association Scale (mJOA) and the radiological results using the Cobb angle, Sagittal Vertical Axis, T1 Slope and alignment (measured by Cobb-T1 Sloppe).

RESULTS

Significant differences were observed in the postoperative improvement of the Nurick scale (p = 0.008) and mJOA (p = 0.018) in the laminoplasty group. In LFP there is a tendency to a greater improvement, but statistical significance is not reached due to the low sample size of this group. No statistically significant differences were observed in the radiological variables. Regarding the total number of complications, a higher number was observed in the laminoplasty group (7 cases) versus LFP (one case), but no statistically significant differences were observed.

CONCLUSIONS

Laminoplasty and LFP are both safe and effective procedures in the treatment of cervical degenerative myelopathy. The findings of our study demonstrate statistically significant clinical improvement based on the Nurick and mJOA scales with laminoplasty. No significant differences in terms of complications or radiological variables were observed between the 2 techniques.

Impact of morphological restoration of the spinal cord from the preoperative to early postoperative periods on C5 palsy development

OBJECTIVE

C5 palsy (C5P) is a known complication of cervical decompression surgery. The tethering effect of the C5 nerve root following the posterior shift of the spinal cord is the most accepted pathologic mechanism for C5P development; however, this mechanism cannot fully explain C5P by itself in clinical practice. Separately, some studies have suggested that preoperative severe spinal cord compression and postoperative morphological changes in the spinal cord affect C5P development; however, no previous study has quantitatively addressed these possibilities. The aim of this study was to examine whether spinal cord morphology and morphological restoration after surgery affect C5P development.

METHODS

The authors reviewed consecutive patients with degenerative cervical myelopathy who underwent laminoplasty including the C3-4 and C4-5 intervertebral disc levels. All participants underwent MRI both preoperatively and within 4 weeks postoperatively. To assess the severity of spinal cord compression, the compression ratio (CR; spinal cord sagittal diameter/transverse diameter) was calculated. As an index of morphological changes in the spinal cord during the early postoperative period, the change rate of CR (CrCR, %) was calculated as CRwithin 4 weeks postoperatively/CRpreoperatively × 100. These measurements were performed at both the C3-4 and C4-5 intervertebral disc levels. The study cohort was divided into C5P and non-C5P (NC5P) groups; then, CR and CrCR, in addition to other radiographic variables associated with C5P development, were compared between the groups.

RESULTS

A total of 114 patients (mean age 67.6 years, 58.8% men) were included in the study, with 5 and 109 patients in the C5P and NC5P groups, respectively. Preoperative CR at both the C3-4 and C4-5 levels was significantly lower in the C5P group than in the NC5P group (0.35 vs 0.44, p = 0.042 and 0.27 vs 0.39, p = 0.021, respectively). Patients with C5P exhibited significantly higher CrCR at the C3-4 level than those without (139.3% vs 119.0%, p = 0.046), but the same finding was not noted for CrCR at the C4-5 level. There were no significant differences in other variables between the groups.

CONCLUSIONS

This study reveals that severe compression of the spinal cord and its greater morphological restoration during the early postoperative period affect C5P development. These findings could support the involvement of segmental cord disorder theory, characterized as the reperfusion phenomenon, in the pathomechanism of C5P, in addition to the tethering effect.

A significant association between C5 nerve sheath tumors and new postoperative weakness

OBJECTIVE

The objective of this study was to determine if patients with nerve sheath tumors affecting the C5 spinal nerve are at greater risk for postoperative weakness than those with similar tumors affecting other spinal nerves contributing to the brachial plexus.

METHODS

A retrospective chart review (1998-2020)identified patients with pathologically confirmed schwannomas or neurofibromas from the C5 to T1 nerves. Patients with plexiform nerve sheath tumors, tumors involving more than 1 nerve, and malignant peripheral nerve sheath tumors were excluded. Collected variables included basic demographics, tumor dimensions, its location relative to the dura, involved nerve level, surgical approach, extent of resection, presenting symptoms, postoperative neurological deficits, and recurrence rate.

RESULTS

Forty-six patients (23 men, 23 women) were identified for inclusion in the study with an average age of 47 ± 17 years, BMI of 28 ± 5 kg/m2, and follow-up of 32 ± 45 months. Thirty-nine patients (85%) had schwannomas and 7 (15%) had neurofibromas. Tumors involved the C5 (n = 12), C6 (n = 11), C7 (n = 14), C8 (n = 6), and T1 (n = 3) nerves. Multivariable logistic regression analysis with an area under the curve of 0.85 demonstrated C5 tumor level as an independent predictor of new postoperative weakness (odds ratio 7.4, p = 0.028). Of those patients with new postoperative weakness, 75% improved and 50% experienced complete resolution of their motor deficits.

CONCLUSIONS

Patients with C5 nerve sheath tumor resections are at higher odds of new postoperative weakness. This may be due to the predominant single innervation of shoulder muscle targets in contrast to other upper extremity muscles that receive input from 2 or more spinal nerves. These findings are important for clinical decision-making and preoperative patient counseling.

Nerve Transfers After Cervical Spine Surgery: Multi-Institutional Case Series and Review of the Literature

BACKGROUND

Up to 10% of cervical spine surgeries are complicated by postoperative weakness. Although many patients recover with nonoperative management, some require surgery for restoration of function.

OBJECTIVE

To present the indications and outcomes of patients undergoing nerve transfers after developing weakness secondary to cervical spine decompression.

METHODS

A retrospective review of patients from 2 academic medical centers who underwent nerve transfer for C5-6 root injury after cervical spine surgery was performed.

RESULTS

Of the 10 treated patients, 9 experienced recovery at last follow-up, demonstrating improvements in strength and motion in the affected muscles. Successful nerve transfers occurred between 3 and 8 months after the index spinal surgery and included spinal accessory nerve to suprascapular nerve, triceps branch to anterior division of the axillary nerve, and/or ulnar or median fascicles to motor branches of the musculocutaneous nerve. The unsuccessful patient underwent nerve transfer surgery approximately 11 months after the index operation and failed to obtain functional recovery.

CONCLUSIONS

Patients who experience C5-6 weakness after cervical spine surgery should be evaluated and considered for nerve transfer surgery if they have continued severe functional deficits at 6 months postoperatively. Earlier referral for nerve transfer is associated with improved functional outcomes in this cohort.

Risk factors for surgical complications in the management of ossification of the posterior longitudinal ligament

BACKGROUND CONTEXT

Ossification of the posterior longitudinal ligament (OPLL) is a progressive, debilitating disease most commonly affecting the cervical spine. When compared to other degenerative pathologies, OPLL procedures carry a significantly higher risk of complications owing to increased case complexity and technical difficulties. Most previous studies have focused on functional outcomes and few have reported on risk factors for postoperative complications in OPLL patients.

PURPOSE

To identify clinical and radiological risk factors of surgical complications following treatment for cervical OPLL STUDY DESIGN: Retrospective review PATIENT SAMPLE: One hundred thirty-one patients with cervical myelopathy secondary to OPLL who underwent surgical decompression with complete 2-year follow-up.

OUTCOME MEASURES

Surgical and medical postoperative complications were analyzed. Revision surgery rates and mortality rates were recorded.

METHODS

Clinical, surgical, and radiological characteristics were collected for each patient. Complications within 30 days were identified. Univariate and multivariate analysis were performed to identify risk factors for surgical complications.

RESULTS

There were 39 (29.8%) surgical complications in the cohort, which included C5 palsy (7.6%), dural tear (3.1%), surgical site infection (3.1%), and epidural hematoma (1.5%). 2-year revision and mortality rates were 4.6% and 2.3%, respectively. Univariate analysis revealed that blood loss ≥750mL (OR 3.42, p=0.028), operative duration ≥5.5 hours (OR 3.16, p=0.008), hill-type OPLL (OR 3.08, p=0.011), K-line (-) OPLL (OR 5.39, p<0.001), and presence of a double-layer sign (OR 3.79, p=0.002) were significant risk factors. In multivariate analysis, only hill-type OPLL (OR 2.61, p=0.048) and K-line (-) OPLL (OR 2.98, p=0.031) were found to be significant. Patients with both hill-type and K-line (-) OPLL had a 3.5 times risk of developing surgical complications (p=0.009).

CONCLUSIONS

Patients with OPLL have a higher risk of perioperative surgical complications if they had a hill-shaped OPLL and K-line (-) OPLL on preoperative imaging studies. To the best of the authors' knowledge, this study is the first to link hill-type and K-line (-) OPLL morphology as risk factors for perioperative surgical complications.

Comparison of Imaging Parameters between a New Cervical Full Lamina Back Shift Spinal Canal Enlargement Technique and Single Open-Door Laminoplasty for Multisegment Cervical Spondylotic Myelopathy

Purpose

To provide imaging evidence of the feasibility and clinical efficacy of a new full lamina back shift spinal canal enlargement technique.

Methods

A retrospective analysis was conducted on 64 patients with multisegment cervical spondylotic myelopathy caused by cervical stenosis. Of these, 32 patients underwent the new full lamina back shift spinal canal enlargement technique (as observation group) and 32 patients underwent single open‐door miniature titanium plate internal fixation (as control group). The computed tomography (CT) data of both groups were imported into Mimics 17.0 software to measure the median sagittal diameter and cross‐sectional area of the spinal canal. Photoshop CS5 was employed to measure the drift distance of the spinal cord on MR images to perform a comparative study of the imaging parameters from the two groups.

Results

The T2‐weighted MR images in both groups showed continuous recovery of the cerebrospinal fluid signal in the C₃–C₇ range. The enlarged spinal canal cross‐sectional area (mm²) of each segment after the new full lamina back shift spinal canal enlargement technique was 130.90 ± 20.52 (C₃), 180.81 ± 18.86 (C₄), 240.48 ± 35.43 (C₅), 145.93 ± 36.94 (C₆), and 153.16 ± 36.28 (C₇), and the enlarged median sagittal diameter (mm) was 5.31 ± 1.13 (C₃), 8.8 ± 1.28 (C₄), 10.28 ± 1.68 (C₅), 9.46 ± 1.48 (C₆), and 9.22 ± 1.12 (C₇). Both parameters were significantly superior to single open‐door miniature titanium plate internal fixation (P < 0.05). No significant difference was detected in the drift distance of the spinal cord between the two groups (P > 0.05).

Conclusion

The new full lamina back shift spinal canal enlargement technique achieved a thorough spinal canal decompression effect on imaging while ensuring a reasonable spinal drift distance and few surgical complications. The clinical curative effect of the new technique was precise.

Prediction of the risk of C5 palsy after posterior laminectomy and fusion with cervical myelopathy using a support vector machine: an analysis of 184 consecutive patients

Background

This study aimed to predict C5 palsy (C5P) after posterior laminectomy and fusion (PLF) with cervical myelopathy (CM) from routinely available variables using a support vector machine (SVM) method.

Methods

We conducted a retrospective investigation based on 184 consecutive patients with CM after PLF, and data were collected from March 2013 to December 2019. Clinical and imaging variables were obtained and imported into univariable and multivariable logistic regression analyses to identify risk factors for C5P. According to published reports and clinical experience, a series of variables was selected to develop an SVM machine learning model to predict C5P. The accuracy (ACC), area under the receiver operating characteristic curve (AUC), and confusion matrices were used to evaluate the performance of the prediction model.

Results

Among the 184 consecutive patients, C5P occurred in 26 patients (14.13%). Multivariate analyses demonstrated the following 4 independent factors associated with C5P: abnormal electromyogram (odds ratio [OR] = 7.861), JOA recovery rate (OR = 1.412), modified Pavlov ratio (OR = 0.009), and presence of C4C5 foraminal stenosis (OR = 15.492). The SVM model achieved an area under the receiver operating characteristic curve (AUC) of 0.923 and an ACC of 0.918. Additionally, the confusion matrix showed the classification results of the discriminant analysis.

Conclusions

The designed SVM model presented satisfactory performance in predicting C5P from routinely available variables. However, future external validation is needed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-021-02476-5.

Preoperative electrophysiologic assessment of C5-innervated muscles in predicting C5 palsy after posterior cervical decompression

PURPOSE

To investigate the feasibility of both needle electromyography (EMG) and proximal nerve conduction studies (NCS) in predicting C5 palsy after posterior cervical decompression.

METHODS

This study included 192 patients with cervical myelopathy undergoing laminoplasty or laminectomy. Preoperatively, all patients accepted bilateral needle EMG detection and proximal NCS that consisted of supramaximally stimulating Erb's point and recording compound muscle action potential (CMAP) from bilateral deltoid.

RESULTS

In the present study, 11 (11/192, 5.7%) patients developed unilateral C5 palsy after operation, and more patients with C5 palsy showed abnormal spontaneous activity in C5-innervated muscles compared to those without C5 palsy (8/11 vs. 16/181, p < 0.05). The sensitivity and specificity of spontaneous activity in C5-innervated muscles in predicting postoperative C5 palsy were 72.7% and 91.2%, respectively. Furthermore, there were significant left-to-right differences of deltoid CMAP amplitudes between the patients with and without C5 palsy (p < 0.05), and this measurement was also demonstrated to be useful for distinguishing patients with C5 palsy from cases without C5 palsy by receiver operating characteristic (ROC) curve analysis (cut-off value: 2.1 mV, sensitivity: 63.6%; specificity: 95.0%). In addition, the sensitivity and specificity of a series application of these two measurements were 63.6% and 100.0%, respectively.

CONCLUSIONS

The findings of this study support the hypothesis that pre-existing progressive C5 root injury may be a risk factor for C5 palsy after posterior cervical decompression. Clinically, the estimation of NCS and needle EMG in C5-innervated muscles may provide additional useful information for predicting C5 palsy after cervical spinal surgery.

LEVEL OF EVIDENCE I

Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

Risk factor analysis of surgery-related complications in primary cervical spine surgery for degenerative diseases using a surgeon-maintained database

AIMS

This study, using a surgeon-maintained database, aimed to explore the risk factors for surgery-related complications in patients undergoing primary cervical spine surgery for degenerative diseases.

METHODS

We studied 5,015 patients with degenerative cervical diseases who underwent primary cervical spine surgery from 2012 to 2018. We investigated the effects of diseases, surgical procedures, and patient demographics on surgery-related complications. As subcategories, the presence of cervical kyphosis ≥ 10°, the presence of ossification of the posterior longitudinal ligament (OPLL) with a canal-occupying ratio ≥ 50%, and foraminotomy were selected. The surgery-related complications examined were postoperative upper limb palsy (ULP) with a manual muscle test (MMT) grade of 0 to 2 or a reduction of two grade or more in the MMT, neurological deficit except ULP, dural tear, dural leakage, surgical-site infection (SSI), and postoperative haematoma. Multivariate logistic regression analysis was performed.

RESULTS

The significant risk factors (p < 0.050) for ULP were OPLL (odds ratio (OR) 1.88, 95% confidence interval (CI) 1.29 to 2.75), foraminotomy (OR 5.38, 95% CI 3.28 to 8.82), old age (per ten years, OR 1.18, 95% CI 1.03 to 1.36), anterior spinal fusion (OR 2.85, 95% CI 1.53 to 5.34), and the number of operated levels (OR 1.25, 95% CI 1.11 to 1.40). OPLL was also a risk factor for neurological deficit except ULP (OR 5.84, 95% CI 2.80 to 12.8), dural tear (OR 1.94, 95% CI 1.11 to 3.39), and dural leakage (OR 3.15, 95% CI 1.48 to 6.68). Among OPLL patients, dural tear and dural leakage were frequently observed in those with a canal-occupying ratio ≥ 50%. Cervical rheumatoid arthritis (RA) was a risk factor for SSI (OR 10.1, 95% CI 2.66 to 38.4).

CONCLUSION

The high risk of ULP, neurological deficit except ULP, dural tear, and dural leak should be acknowledged by clinicians and OPLL patients, especially in those patients with a canal-occupying ratio ≥ 50%. Foraminotomy and RA were dominant risk factors for ULP and SSI, respectively. An awareness of these risks may help surgeons to avoid surgery-related complications in these conditions. Cite this article: Bone Joint J 2021;103-B(1):157-163.

Therapeutic Impact of Traction Release After C5 Nerve Root Motor Evoked Potential (MEP) Alerts in Cervical Spine Surgery

STUDY DESIGN

A retrospective review of 40,919 cervical spine surgeries monitored with motor evoked potentials (MEPs) from a multi-institutional intraoperative neuromonitoring database.

OBJECTIVE

The objective of this study was to determine the clinical impact of interventions prompted by C5 spinal nerve root MEP alerts.

SUMMARY OF BACKGROUND DATA

MEPs have been shown to diagnose acute C5 palsies, but additional data are needed regarding the clinical impact of interventions in response to C5 MEP alerts.

MATERIALS AND METHODS

Procedures with isolated C5 MEP alerts were categorized as fully resolved, partially resolved, or unresolved based on the status of signals at closure. Clinical outcomes were based on neurological assessment in the immediate postoperative period. The sensitivity, specificity, likelihood ratios, and odds ratios (ORs) of C5 MEP alerts for acute C5 palsies were calculated.

RESULTS

The odds of an acute C5 palsy greatly increased if there was a C5 MEP alert [OR=340.9; 95% confidence (CI): 173.0, 671.6; P<0.0001], and increased further if the alert persisted through closure (OR=820.8; 95% CI: 398.1, 1692.0; P<0.0001). Relative to procedures with unresolved C5 MEP alerts, the risk of an acute C5 palsy significantly decreased if a C5 MEP alert was fully resolved by closure (OR=0.07; 95% CI: 0.02, 0.25; P<0.0001). For alerts resolved during positioning or exposure, 90.9% were resolved with the release of positional traction, and for resolved alerts that occurred after exposure, 36.3% involved just traction release, 14.1% involved both traction release and surgical action, and 30.3% involved just surgical action. The sensitivity of C5 MEP alerts for acute C5 palsies was anesthetic dependent: 89.7% (26/29) in the total intravenous regimen cohort but just 50.0% (10/20) in the inhalational anesthesia cohort.

CONCLUSIONS

The timely release of positional traction is an effective intervention for resolving C5 MEP alerts and reducing the odds of an acute postoperative C5 palsy. Surgical maneuvers, such as the release of distraction or graft adjustment, should be attempted in conjunction with traction release depending on the surgical context of the alert.

LEVEL OF EVIDENCE

Level IV.

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.

Multiple level anterior cervical discectomy and fusion versus posterior laminectomy for the management of multilevel cervical spondylotic myelopathy: clinical and radiological outcome

Background

Though both anterior and posterior approach are used for the management of multilevel cervical spondylotic myelopathy (CSM), the choice between both approaches remains to be of considerable debate.

Aim of the work

The aim of the study was to evaluate the clinical and radiographic outcomes of patients with multiple level CSM who underwent posterior laminectomy (PL) versus anterior cervical discectomy and fusion (ACDF).

Methods

This is a retrospective comparative study of 30 patients, with multiple level CSM managed by the authors, either by PL (n = 15) or ACDF (n = 15). Clinical outcome was assessed at 1, 3, 6, and 12 months postoperatively using the modified Japanese Orthopedic Association scale (mJOA) while the postoperative radiographic changes represented by the Cobb’s angle variation was recorded at 12 months postoperatively and compared with preoperative values. Also, the incidence of postoperative complications and neurological deterioration was recorded and studied between the two groups. Study duration was for 2 years from December 2014 to December 2016.

Results

Both the ACDF and PL groups showed an improvement in the mJOA score mean value at 1 year after surgery in comparison with the preoperative evaluation data; however, on comparing between both groups at 1 year postoperatively, the median percent of increase in mJOA score was significantly higher in the ACDF group compared with the PL group (33.3% vs 22.2% respectively). On the other hand, the Cobb’s angle percent of change 1 year after surgery showed a median percent of increase of 18.7% in the ACDF group in contrast to a median decrease of − 11.1% in the PL group which was statistically significant. Minimal complications were reported in both groups.

Conclusion

Both PL and ACDF are effective modalities for the surgical management of multilevel CSM showing good clinical outcome; however, when compared with the posterior approach, there was a statistical significant difference favoring ACDF regarding the median percent of increase in mJOA score and the postoperative Cobb’s angle improvement.

Anterior Cervical Decompression and C5 Palsy: A Systematic Review and Meta-analysis of Three Reconstructive Surgeries

STUDY DESIGN

A systematic review and meta-analysis were performed with the literature including the case of C5 palsy following anterior cervical decompression surgery.

OBJECTIVE

The aim of this study was to compare three reconstructive procedures of anterior cervical decompression, the incidences of delayed C5 palsy and other complications were assessed.

SUMMARY OF BACKGROUND DATA

Delayed C5 palsy is now a well-known complication after cervical decompression surgery. The etiology of C5 palsy has been studied, especially after posterior surgery. However, in anterior surgery there has been a lack of investigation due to procedure variation. Additionally, limited evidence exists regarding the risk of C5 palsy in surgical procedures.

METHODS

We performed an extensive literature search for C5 palsy and other complications with ACDF, ACCF, and their combination (Hybrid). Gross incidences of C5 palsy after these three procedures were compared, and specific superiorities (or inferiorities) were investigated via comparison of binary outcomes between two of three groups using odds ratios (OR).

RESULTS

Twenty-six studies met the inclusion criteria. A total of 3098 patients were included and 5.8% of those developed C5 palsy. Meta-analyses demonstrated that ACDF had a lower risk of palsy than ACCF (OR 0.36, 95% confidence interval [CI] 0.16-0.78), whereas ACDF versus Hybrid (OR 0.60, 95% CI 0.24-1.51) and Hybrid versus ACCF (OR 1.11, 95% CI 0.29-4.32) were not significantly different. Although these differences were not observed in shorter lesion subgroups, there were significant differences between the three procedures in longer lesion subgroups (P = 0.0005). Meta-analyses revealed that in longer lesions, ACDF had a significantly lower incidence than ACCF (OR 0.42, 95% CI 0.22-0.82). Additionally, Hybrid surgery was noninferior for palsy occurrence compared to ACCF, and suggested a trend for reduced rates of other complications compared to ACCF.

CONCLUSION

ACDF may yield better outcomes than Hybrid and ACCF. Furthermore, Hybrid may have advantages over ACCF in terms of surgical complications.

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.

Direct Involvement of Concomitant Foraminotomy for Radiculomyelopathy in Postoperative Upper Limb Palsy in Cervical Laminoplasty

OBJECTIVE

Although concomitant foraminotomy has been reported to increase the risk of postoperative upper limb palsy (ULP) in cervical laminoplasty, the specific effects of concomitant foraminotomy on ULP remain uncertain. This study aimed to clarify the effect of concomitant foraminotomy on ULP in cervical laminoplasty.

METHODS

We identified 19 patients who developed ULP after laminoplasty with concomitant foraminotomy for radiculomyelopathy with nerve root impingement (laminoplasty with concomitant foraminotomy group [F-group]) from 4080 patients who underwent primary cervical laminoplasty at 27 affiliated institutions between 2012 and 2018. An age- and sex-matched control group comprised patients who developed ULP after laminoplasty without concomitant foraminotomy (n = 76, 4:1 ratio with F-group). Collected data included the time of onset and distribution of ULP (side and level). The site of foraminotomy was recorded in the F-group.

RESULTS

The F-group showed a significantly higher incidence of ULP than the candidates for the control group (15.1% vs. 3.1%, P < 0.001). The site of foraminotomy was consistent with the distribution of ULP in 79% (15 of 19 patients) of the F-group. The F-group showed a significantly higher proportion of preoperative upper-limb muscle weakness (74% vs. 37%, P = 0.005) and early-onset ULP occurring by postoperative day 1 (63% vs. 33%, P = 0.02) compared with the control group.

CONCLUSIONS

Our results indicate that the foraminotomy procedure in the stenotic foramen is directly involved in ULP. Combined with a previous report suggesting that early-onset ULP is associated with thermal nerve damage, our results indicate that thermal nerve damage partly explains the increased incidence of ULP in the F-group.

Thin Cervical Spinal Cord Between Ossifications of the Ligamentum Flavum and the Posterior Longitudinal Ligament: Case Report and Literature Review

BACKGROUND

Cervical ossification of the ligamentum flavum (OLF) is a rare condition; however, the coexistence of OLF and ossification of the posterior longitudinal ligament (OPLL) is extremely uncommon. These can exist simultaneously and cause thinning of the cervical spinal cord. Sufficient decompression, dural ossification, semispinalis dissection, and postoperative kyphosis were evaluated. We report the successful treatment of coexisting cervical OLF and OPLL.

CASE DESCRIPTION

A 70-year-old man had been experiencing weakness in the left knee and clumsiness in the left hand for 6 months. Hemiparesis was considered; however, magnetic resonance imaging revealed a cervical spinal lesion. Hence a spine surgeon diagnosed the patient with severe stenosis with OLF at the C2-C3 levels and OPLL at the C2-C4 levels. The patient presented with spastic gait and left-hand motor weakness. Computed tomography scan revealed the disappearance of the black line, indicating dural ossification surrounding the OLF. OPLL was observed in 61.5% of the C2 spinal canal. The K-line was (-); however, the alternative K-line between the C1 and C7 level was (+). Posterior laminectomy at the C2-C3 levels and laminoplasty at the C4-C7 levels with muscle preservation resulted in sufficient decompression. The patient's symptoms improved, and cervical alignment was maintained 2 years after surgery.

CONCLUSIONS

An alternative K-line comprised successful treatment for coexisting cervical OLF and OPLL. Surgeons must evaluate the severity of adhesion, damage of the paraspinal muscles, and necessity of posterior corrective surgery along with the patient's comorbidities and possible postoperative complications.

C5 Palsy After Cervical Spine Decompression: Topographic Correlation With C6 Chassaignac Tubercle?: A Fresh-Cadaveric Study of the Cervical Spine and Rediscussion of Etiological Hypotheses

STUDY DESIGN

Cadaveric study on fresh unprocessed, nonpreserved, undyed specimens, which has not previously been reported.

OBJECTIVE

Our aim was to explore the possible topographic correlation of the C5 nerve root with regards to its course and regional relation to C6 Chassaignac tubercle.

SUMMARY OF BACKGROUND DATA

C5 palsy is reported amongst the most frequent postoperative complications of cervical spinal procedures. We hypothesized that etiologic mechanisms proposed thus far in the current literature, although with some plausible explanation, still cannot explain why the C5 nerve root and not any other level suffer a postoperative palsy.

METHODS

Six fresh cadavers had extensive layer by layer dissection performed by two surgeons (one of whom has experience as an anatomy demonstrator and dissector). Roots of brachial plexus were exposed in relation to cervical transverse processes. Photographs were taken at each stage of the exposure.

RESULTS

We observed a close relation of the path of the C5 nerve root with the C6 tubercle bilaterally. Moreover, we noted a steeper descent of C5 in comparison with the other adjacent roots.

CONCLUSION

Steeper angle of the C5 nerve root and close proximity to C6 Chassaignac tubercle may play a role in predisposing it to neuropraxia. Detailed anatomical photographs on fresh unprocessed cadaveric specimens are novel. Peculiar anatomical features and recent experimental evidence discussed do highlight a postganglionic extraforaminal etiology corresponding well to the demographic meta-analysis data on clinical features of postoperative C5 palsy. Exploring an alternative unified "neurophysiologic stress and critical tipping point" etiological model that encompasses current theories and correlates known metanalyses observations, we believe further studies would be prudent to ascertain/refute these findings.

LEVEL OF EVIDENCE

3.

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.

Anterior controllable antidisplacement and fusion surgery for the treatment of extensive cervico-thoracic ossification of posterior longitudinal ligament with severe myelopathy: case report and literature review

OPLL generally occurs in the cervical spine and involves no more than three vertebral segments, while extensive OPLL that involves the cervico-thoracic spine and spans over multiple segments is rare. Surgically it is difficult to achieve a satisfactory clinical outcome without surgical complications via the traditional anterior or posterior approaches. We report the first application of Anterior controllable antidisplacement and fusion (ACAF) in treating extensive cervico-thoracic OPLL. A 45-year old patient experienced severe walking disturbance, bladder and bowel dysfunction for 5 months after a fall. His preoperative Japanese Orthopedic Association (JOA) score was 8 of 17. Preoperative CT and MRI demonstrated a K-line (-) and mixed-type extensive OPLL from C2 to T2, causing significant cord compression. After ACAF surgery, neurological symptoms improved immediately without postoperative complications. Postoperative CT and MRI scanning showed restoration of spinal canal cross section and cord decompression. At 6 months he was able to stand and walk again without assistance and urinary bladder and bowel function returned to normal completely. At 15 months his JOA score was 14 of 17. ACAF surgery provides a promising alternative for the treatment of extensive cervico-thoracic OPLL.

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.

Intraoperative Shoulder Traction as Cause of C5 Palsy: Magnetic Resonance Imaging Study

OBJECTIVE

During surgery, shoulder traction is often used for better fluoroscopic imaging of the lower cervical spine. Traction on the C5 root has been implicated as a potential cause of C5 palsy after cervical spine surgery. Using magnetic resonance imaging, this study was undertaken to determine the impact of upper extremity traction on the C5 root orientation.

METHODS

In this study, 5 subjects underwent coronal magnetic resonance imaging of the cervical spine and left brachial plexus. Using a wrist restraint, sequential traction on the left arm with 10, 20, and 30 lb. was applied. Measurements of the angle between the spinal axis and C5 nerve root and the angle between the C5 nerve root and the upper trunk of the brachial plexus were obtained. The measurements were taken by a trained neuroradiologist and analyzed for significance.

RESULTS

The angle between the C5 nerve root and the vertical spinal axis remained within 3 and 4 degrees of the mean and was not found to be associated with increased traction weight (P = 0.753). The angle between the C5 root and the upper trunk increased with increasing weight and was found to be statistically significant (P = 0.003).

CONCLUSIONS

While the cause of C5 palsy is likely multifactorial, this study provides evidence that, in the awake volunteer, upper extremity traction leads to C5 root and upper trunk tension. These results suggest that shoulder traction in the anesthetized patient could lead to tension of the C5 nerve root and subsequent injury and palsy.

Impact of Multifidus Muscle Swelling on C5 Palsy After Cervical Laminoplasty

STUDY DESIGN

Retrospective radiological analysis OBJECTIVE.: The aim of this study was to identify the effects of posterior cervical muscle swelling on C5 palsy (C5P) by evaluating early postoperative magnetic resonance (MR) images.

SUMMARY OF BACKGROUND DATA

Cervical laminoplasty is an established technique, but the risk of C5P after surgery has not been fully resolved. Studies have reported that lateral stretching and postoperative swelling of the multifidus muscle may cause stretching of the medial branches and cervical nerves.

METHODS

A total of 214 C5 nerves of 107 consecutive patients who underwent laminoplasty were examined. We reviewed their demographic and surgical data and radiographic and MR images as parameters, including the axial cross-sectional area (CSA) of the posterior muscles. The patients and C5 nerves were divided into C5P and non-C5P groups. The parameters and changes were compared between the two groups to examine correlations with C5P.

RESULTS

In demographic data, age, sex, history of smoking, diabetes mellitus, and preoperative Japanese Orthopedic Association scores were not significantly different between the groups. Only body mass index (BMI) was significantly higher in the C5P group. Regarding the surgical and imaging data, the number of laminoplasty, operative time, decompression trough width, cervical sagittal alignment, preoperative spinal cord rotation, and posterior shift of the spinal cord were not significantly different, but the multifidus CSA change ratio was significantly higher in the C5P group. Multiple logistic regression analyses revealed that the multifidus CSA change ratio and BMI were significant independent factors.

CONCLUSION

Multifidus swelling is associated with C5P, possibly through traction of the C5 nerve via the medial branches of the cervical dorsal rami. The medial branch is the shortest of the dorsal rami and may have the largest effect by traction force. Therefore, a gentle maneuver of the deep posterior muscles during surgery is a potential countermeasure to prevent C5P.

LEVEL OF EVIDENCE

3.

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.

Factors Associated With C5 Palsy Following Cervical Spine Surgery: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

C5 palsy (C5P) is a not uncommon and disabling postoperative complication with a reported incidence varying between 0% and 30%. Among others, one explanation for its occurrence includes foraminal nerve root tethering. Although different risk factors have been reported, controversy about its causation and prevention persists. Inconsistent study findings contribute to the persistent ambiguity leading to an assumption of a multifactorial nature of the underlying C5P pathophysiology. Here, we report the results of a systematic review on C5P with narrow inclusion criteria in the hope of elucidating risk factors for C5P due to a common pathophysiological mechanism.

METHODS

Electronic databases from inception to March 9, 2019 and references of articles were searched. Narrow inclusion criteria were applied to identify studies investigating demographic, clinical, surgical, and radiographic factors associated with postoperative C5P.

RESULTS

Sixteen studies were included after initial screening of 122 studies. Eighty-four risk factors were analyzed; 27 in ≥2 studies and 57 in single studies. The pooled prevalence of C5P was 6.0% (range: 4.2%-24.1%) with no consistent evidence that C5P was associated with demographic, clinical, or specific surgical factors. Of the radiographic factors assessed, specifically decreased foraminal diameter and preoperative cord rotation were identified as risk factors for C5P.

CONCLUSION

Although risk factors for C5P have been reported, ambiguity remains due to potentially multifactorial pathophysiology and study heterogeneity. We found foraminal diameter and cord rotation to be associated with postoperative C5P occurrence in our meta-analysis. These findings support the notion that factors contributing to, and acting synergistically with foraminal stenosis increase the risk of postoperative C5P.

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.

Extended Laminoplasty for Ossification of Posterior Longitudinal Ligament Involving the C2 Segment

BACKGROUND

To evaluate effectiveness and safety of extended laminoplasty for the treatment of ossification of posterior longitudinal ligament (OPLL) involving the C2 segment.

METHODS

A total of 132 cases who accepted laminoplasty for treating the OPLL from 2010 to 2015 were included and divided into Group A (n = 26, with C2 OPLL and C2-C7 laminoplasty), Group B (n = 29, with C2 OPLL and C3-C7 laminoplasty), and Group C (n = 77, without C2 OPLL and had C3-C7 laminoplasty). Clinical and radiologic outcomes were compared among the 3 groups.

RESULTS

At the final visit, significant improvements in Japanese Orthopedic Association score, Neck Disability Index, Health-Related Quality-of-Life Short Form 36 Physical Component Summary, and Visual Analog Scale score in neck were observed in all 3 groups. However, all the C2-C7 Cobb angle, C2-C3 Cobb angle, sagittal vertical axis, and number of cases with cervical or segmental kyphosis in the 3 groups were not significantly changed. Although total blood loss, operation time, maximum Visual Analog Scale score in neck, incidence of axial pain, change of C2-C7, or sagittal vertical axis in Group A were all significantly larger than that in Group B or Group C, differences in neurologic recovery rate, Neck Disability Index, Health-Related Quality-of-Life Short Form 36 Physical Component Summary, change of the C2-C3 Cobb angle, and incidence of cervical or segmental malalignment among the 3 groups were not significant at the final visit.

CONCLUSIONS

If decompression indication for cases with OPLL involving the C2 segment was appropriate, extended laminoplasty up to the C2 segment could provide satisfactory neurologic recovery and would not accelerate cervical or segmental malalignment progression.

Anterior and Posterior Approaches for Cervical Myelopathy: Clinical and Radiographic Outcomes

STUDY DESIGN

A retrospective cohort study.

OBJECTIVE

The aim of this study was to identify advantages and disadvantages of the anterior and posterior approaches in the treatment of cervical stenosis and myelopathy.

SUMMARY OF BACKGROUND DATA

Both anterior and posterior surgical approaches for cervical stenosis and myelopathy have been shown to result in improvement in health-related outcomes. Despite the evidence, controversy remains regarding the best approach to achieve decompression and correct deformity.

METHODS

We retrospectively reviewed patients with cervical stenosis and myelopathy who had undergone anterior cervical fusion and instrumentation (n = 38) or posterior cervical laminectomy and instrumentation (n = 51) with at least 6 months of follow-up. Plain radiographs, magnetic resonance imaging, and computed tomography scans, as well as health-related outcomes, including Visual Analog Scale for neck pain, Japanese Orthopedic Association score for myelopathy, Neck Disability Index, and Short Form-36 Health Survey, were collated before surgery and at follow-up (median 12.0 and 12.1 months for anterior and posterior group, respectively).

RESULTS

Both anterior and posterior approaches were associated with significant improvements in all studied quality of life parameters with the exception of general health in the anterior group and energy and fatigue in the posterior group. In the anterior group, follow-up assessment revealed a significant increase in C2-7 lordosis. Both approaches were accompanied by significant increases in C2-7 sagittal balance [sagittal vertical axis (SVA)]. There were two complications in the anterior group and nine complications in the posterior group; the incidence of complications between the two groups was not significantly different.

CONCLUSION

When the benefits of one approach over the other are not self-evident, the anterior approach is recommended, as it was associated with a shorter hospital stay and more successful restoration of cervical lordosis than posterior surgery.

LEVEL OF EVIDENCE

3.

Modified expansive laminoplasty and fusion compared with anterior cervical surgeries in treating four-level cervical spondylotic myelopathy

Objective

To compare modified expansive laminoplasty and fusion (MELF) with anterior cervical corpectomy and fusion (ACCF), and anterior cervical discectomy and fusion (ACDF), in treating four-level cervical spondylotic myelopathy (CSM).

Methods

This retrospective study included patients with four-level CSM who had undergone surgery at the Affiliated Hospital of Qingdao University between January 2013 and May 2015. D-values, Cobb’s angle, Japanese Orthopaedic Association (JOA) score and quality of life (SF-36 scores) were compared between patients treated with ACCF/ACDF versus MELF.

Results

Twenty-six patients who underwent ACCF/ACDF and 26 who underwent MELF were included, and all showed bone fusion following treatment. The most common complications were dysphasia (12/26) in the ACCF/ACDF group and axial neck pain (7/26) in the MELF group. C5 nerve root palsy was not observed in either group. D value and Cobb’s angle changes showed that ACDF/ACCF was more effective in curve correction than MELF. Postoperative improvements in JOA and SF-36 scores were noted in both groups, with no statistically significant between-group differences.

Conclusion

Anterior and posterior approaches may produce similar clinical outcomes in the surgical management of four-level CSM. MELF may avoid known complications of the posterior approach.