Comparison of Anterior and Posterior Surgery for Degenerative Cervical Myelopathy: An MRI-Based Propensity-Score-Matched Analysis Using Data from the Prospective Multicenter AOSpine CSM North America and International Studies

Three-dimensional Spinal Canal Morphometric Analysis and Relevant Spinal Cord Occupational Ratios in Congenital Cervical Spinal Stenosis: A Classification Algorithm of the Stenosis Phenotypes and Data-driven Decompression Approach

OBJECTIVES

No standardized magnetic resonance imaging (MRI) parameters have defined the 3-dimensional morphoanatomy and relevant spinal cord occupation ratios (occupation of spinal cord dimensions/similar dimensions within the spinal canal) in congenital cervical stenosis (CCS).

METHODS

A retrospective, comparative analysis was conducted on 200 patients >18 years of age with myelopathy and CCS (mean age, 52.4 years) and 200 age-matched controls with no myelopathy or radiculopathy. The variables assessed from high resolution MRI included sagittal and axial spinal canal dimensions (MRI Torg-Pavlov ratios) from C3 to C7. Morphometric dimensions from the sagittal retrodiscal and retrovertebral regions as well as axial MRI dimensions were compared. Sagittal and axial spinal cord occupation ratios were defined and correlated with spinal canal dimensions.

RESULTS

Multivariate analyses indicated reduced sagittal and axial anteroposterior (AP) spinal canal dimensions and a large reduction in transverse spinal canal dimensions at all spinal levels. There was a small significant correlation between AP sagittal spinal canal dimensions and axial transverse spinal canal dimensions at C3-C5, but not at C5-C6. Small correlations were noted between AP sagittal spinal canal dimensions and AP axial spinal cord and axial cross-sectional area occupation ratios at C3-C6, but there was no correlation with axial mediolateral spinal cord occupation ratios.

CONCLUSIONS

The stenosis effect can involve any dimension, including the transverse spinal canal dimension, independent of other dimensions. Owing to the varied observed morphoanatomies, a classification algorithm that defines CCS specific phenotypes was formulated. Objectivizing the stenosis morphoanatomy may allow for data-driven patient-focused decompression approaches in the future.

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.

Current Concepts of Cervical Spine Alignment, Sagittal Deformity, and Cervical Spine Surgery

There are not many reports on cervical spine alignment, and only a few analyze ideal surgical approaches and optimal amounts of correction needed for the various types of deformity. We comprehensively reviewed the present literature on cervical spinal deformities (with or without myelopathy) and their surgical management to provide a framework for surgical planning. A general assessment of the parameters actually in use and correlations between cervical and thoracolumbar spine alignment are provided. We also analyzed posterior, anterior, and combined cervical surgical approaches and indications for the associated techniques of laminoplasty, laminectomy and fusion, and anterior cervical discectomy and fusion. Finally, on the basis of the NDI, SF-36, VAS, and mJOA questionnaires, we fully evaluated the outcomes and measures of postoperative health-related quality of life. We found the need for additional prospective studies to further enhance our understanding of the importance of cervical alignment when assessing and treating cervical deformities with or without myelopathy. Future studies need to focus on correlations between cervical alignment parameters, disability scores, and myelopathy outcomes. Through this comprehensive literature review, we offer guidance on practical and important points of surgical technique, cervical alignment, and goals surgeons can meet to improve symptoms in all patients.

Anterior direct decompression significantly relieves spinal cord high signal in patients with ossification of the posterior longitudinal ligament: a case-control study

BACKGROUND

In patients with cervical spondylotic myelopathy caused by ossification of the posterior longitudinal ligament, high cord signal (HCS) is frequently observed. However, limited research has investigated the variations in HCS improvement resulting from different surgical approaches. This study aims to explore the potential relationship between the choice of surgical approach and the postoperative improvement of intramedullary high signal in ossification of the posterior longitudinal ligament (OPLL) patients.

METHODS

We extensively reviewed the patients' medical records, based on which demographic information such as gender, age, and body mass index (BMI) were recorded, and assessed the severity of the patients' neurological status preoperatively and postoperatively by using the Japanese Orthopedic Association score (JOAs), focusing on consecutive preoperative and postoperative Magnetic resonance imaging (MRI) T2WI measurements, to study the statistical correlation between the improvement of HCS and the choice of surgical approach.

RESULTS

There were no significant differences in demographic, imaging parameters, and clinical symptoms between patients undergoing anterior and posterior surgery (p > 0.05, Table 1). However, both improvement in JOAs (Recovery2) and improvement in HCS (CR2) were significantly better in the anterior surgery group two years after surgery (p < 0.05, Table 1). Multifactorial logistic regression analysis revealed that posterior surgery and higher preoperative signal change ratio (SCR) were identified as risk factors for poor HCS improvement at the two-year postoperative period (p < 0.05, Table 2). Table 1 Differences in demographic, imaging parameters, and clinical symptoms in patients with anterior and posterior approach Anterior approach Posterior approach P-Values Demographic data  Sex (male/female) 10/12 6/17 0.175  Age 58.59 ± 5.68 61.43 ± 9.04 0.215  Hypertension 14/8 14/9 0.848  Diabetes 16/6 19/4 0.425  BMI 25.58 ± 4.72 26.95 ± 4.58 0.331  Smoking history 19/3 16/7 0.175 Preoperative measured imaging parameters  Preoperative SCR 1.615 ± 0.369 1.668 ± 0.356 0.623  CR1 0.106 ± 0.125 0.011 ± 0.246 0.08  CNR 0.33 ± 0.073 0.368 ± 0.096 0.15  C2-7 Cobb angle 8.977 ± 10.818 13.862 ± 13.191 0.182  SVA 15.212 ± 8.024 17.46 ± 8.91 0.38  mK-line INT 3.694 ± 3.291 4.527 ± 2.227 0.323 Imaging follow-up  6 months postoperative SCR 1.45 ± 0.44 1.63 ± 0.397 0.149  2 years postoperative SCR 1.26 ± 0.19 1.65 ± 0.35 0.000**  CR2 0.219 ± 0.14 - 0.012 ± 0.237 0.000** Clinical symptoms  Preoperative JOAs 10.64 ± 1.59 10.83 ± 1.47 0.679  6 months postoperative JOAs 11.82 ± 1.37 11.65 ± 1.4 0.69  2 years postoperative JOAs 14.18 ± 1.01 12.52 ± 2.06 0.001**  Recovery1 0.181 ± 0.109 0.128 ± 0.154 0.189  Recovery2 0.536 ± 0.178 0.278 ± 0.307 0.001** *, statistical significance (p < 0.05). **, statistical significance (p < 0.01) BMI = body mass index. SCR = the signal change ratio between the localized high signal and normal spinal cord signal at the C7-T1 levels. CR1 = the regression of high cord signals at 6 months postoperatively (i.e., CR1 = (Preoperative SCR-SCR at 6 months postoperatively)/ Preoperative SCR). CR2 = the regression of high cord signal at 2 years postoperatively (i.e., CR2 = (Preoperative SCR-SCR at 2 years postoperatively)/ Preoperative SCR). CNR = canal narrowing ratio. SVA = sagittal vertical axis. mK-line INT = modified K-line interval. JOAs = Japanese Orthopedic Association score. Recovery1 = degree of JOAs recovery at 6 months postoperatively (i.e., Recover1 = (JOAs at 6 months postoperatively-Preoperative JOAs)/ (17- Preoperative JOAs)). Recovery2 = degree of JOAs recovery at 2 years postoperatively (i.e., Recover2 = (JOAs at 2 years postoperatively-Preoperative JOAs)/ (17-Preoperative JOAs)) Table 2 Linear regression analyses for lower CR2 values 95% CI P value Uni-variable analyses Demographic data  Sex (male/female) - 0.01 0.221 0.924  Age - 0.015 0.003 0.195  Hypertension - 0.071 0.204 0.334  Diabetes - 0.195 0.135 0.716  BMI - 0.375 0.422 0.905  Smoking history - 0.249 0.077 0.295  Surgical approach - 0.349 - 0.113 0.000# Preoperative measured imaging parameters  C2-7 Cobb angle - 0.009 0.002 0.185  SVA - 0.008 0.008 0.995  mK-line INT - 0.043 0.005 0.122  Preoperative SCR 0.092 0.445 0.004#  CR1 0.156 0.784 0.004#  CNR - 0.76 0.844 0.918 Multi-variable analyses  Surgical approach - 0.321 - 0.118 0.000**  Preoperative SCR 0.127 0.41 0.000**  CR1 - 0.018 0.501 0.067 #, variables that achieved a significance level of p < 0.1 in the univariate analysis *statistical significance (p < 0.05). **statistical significance (p < 0.01) BMI = body mass index. SCR = the signal change ratio between the localized high signal and normal spinal cord signal at the C7-T1 levels. CR1 = the regression of high cord signals at 6 months postoperatively (i.e., CR1 = (Preoperative SCR-SCR at 6 months postoperatively)/ Preoperative SCR). CR2 = the regression of high cord signal at 2 years postoperatively (i.e., CR2 = (Preoperative SCR-SCR at 2 years postoperatively)/ Preoperative SCR). CNR = canal narrowing ratio. SVA = sagittal vertical axis. mK-line INT = modified K-line interval CONCLUSIONS: For patients with OPLL-induced cervical spondylotic myelopathy and intramedullary high signal, anterior removal of the ossified posterior longitudinal ligament and direct decompression offer a greater potential for regression of intramedullary high signal. At the same time, this anterior surgical strategy improves clinical neurologic function better than indirect decompression in the posterior approach.

Comparison of Postoperative Opioid Use After Anterior Cervical Diskectomy and Fusion or Posterior Cervical Fusion

INTRODUCTION

Posterior cervical fusion (PCF) and anterior cervical diskectomy and fusion (ACDF) are two main surgical management options for the treatment of cervical spondylotic myelopathy. Although ACDF is less invasive than PCF which should theoretically reduce postoperative pain, it is still unknown whether this leads to reduced opioid use. Our objective was to evaluate whether PCF increases postoperative opioid use compared with ACDF.

METHODS

We retrospectively identified all patients undergoing 2-level to 4-level ACDF or PCF at a single center from 2017 to 2021. Our state's prescription drug-monitoring program was queried for filled opioid prescriptions using milligrams morphine equivalents (MMEs) up to 1 year postoperatively. In-hospital opioid use was collected from the electronic medical record. Bivariate statistics compared ACDF and PCF cohorts. Multivariate linear regression was done to assess independent predictors of in-hospital opioid use and short-term (0 to 30 days), subacute (30 to 90 days), and long-term (3 to 12 months) opioid prescriptions.

RESULTS

We included 211 ACDF patients and 91 PCF patients. Patients undergoing PCF used more opioids during admission (126.7 vs. 51.0 MME, P < 0.001) and refilled more MMEs in the short-term (118.2 vs. 86.1, P = 0.001) but not subacute (33.6 vs. 19.7, P = 0.174) or long-term (85.6 vs. 47.8, P = 0.310) period. A similar percent of patients in both groups refilled at least one prescription after 90 days (39.6% vs. 33.2%, P = 0.287). PCF (β = 56.7, P = 0.001) and 30-day preoperative MMEs (β = 0.28, P = 0.041) were associated with greater in-hospital opioid requirements. PCF (β = 26.7, P = 0.039), C5 nerve root irritation (β = 51.4, P = 0.019), and a history of depression (β = 40.9, P < 0.001) were independently associated with 30-day postoperative MMEs.

CONCLUSIONS

PCF is initially more painful than ACDF but does not lead to persistent opioid use. Surgeons should optimize multimodal analgesia protocols to reduce long-term narcotic usage rather than change the surgical approach.Level of Evidence:III.

Patient-Reported Outcomes Following Anterior and Posterior Surgical Approaches for Multilevel Cervical Myelopathy

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

To compare health-related quality of life (HRQoL) outcomes between approach techniques for the treatment of multilevel degenerative cervical myelopathy (DCM).

SUMMARY OF BACKGROUND DATA

Both anterior and posterior approaches for the surgical treatment of cervical myelopathy are successful techniques in the treatment of myelopathy. However, the optimal treatment has yet to be determined, especially for multilevel disease, as the different approaches have separate complication profiles and potentially different impacts on HRQoL metrics.

MATERIALS AND METHODS

Retrospective review of a prospectively managed single institution database of patient-reported outcome measures after 3 and 4-level anterior cervical discectomy and fusion (ACDF) and posterior cervical decompression and fusion (PCDF) for DCM. The electronic medical record was reviewed for patient baseline characteristics and surgical outcomes whereas preoperative radiographs were analyzed for baseline cervical lordosis and sagittal balance. Bivariate and multivariate statistical analyses were performed to compare the two groups.

RESULTS

We identified 153 patients treated by ACDF and 43 patients treated by PCDF. Patients in the ACDF cohort were younger (60.1 ± 9.8 vs . 65.8 ± 6.9 yr; P < 0.001), had a lower overall comorbidity burden (Charlson Comorbidity Index: 2.25 ± 1.61 vs . 3.07 ± 1.64; P = 0.002), and were more likely to have a 3-level fusion (79.7% vs . 30.2%; P < 0.001), myeloradiculopathy (42.5% vs . 23.3%; P = 0.034), and cervical kyphosis (25.7% vs . 7.69%; P = 0.027). Patients undergoing an ACDF had significantly more improvement in their neck disability index after surgery (-14.28 vs . -3.02; P = 0.001), and this relationship was maintained on multivariate analysis with PCDF being independently associated with a worse neck disability index (+8.83; P = 0.025). Patients undergoing an ACDF also experienced more improvement in visual analog score neck pain after surgery (-2.94 vs . -1.47; P = 0.025) by bivariate analysis.

CONCLUSIONS

Our data suggest that patients undergoing an ACDF or PCDF for multilevel DCM have similar outcomes after surgery.

Selecting the lowest instrumented vertebra in a multilevel posterior cervical fusion across the cervicothoracic junction: a biomechanical investigation

OBJECTIVE

Posterior cervical fusion is a common surgical treatment for patients with myeloradiculopathy or regional deformity. Several studies have found increased stresses at the cervicothoracic junction (CTJ) and significantly higher revision surgery rates in multilevel cervical constructs that terminate at C7. The purpose of this study was to investigate the biomechanical effects of selecting C7 versus T1 versus T2 as the lowest instrumented vertebra (LIV) in multisegmental posterior cervicothoracic fusion procedures.

METHODS

Seven fresh-frozen cadaveric cervicothoracic spines (C2-L1) with ribs intact were tested. After analysis of the intact specimens, posterior rods and lateral mass screws were sequentially added to create the following constructs: C3-7 fixation, C3-T1 fixation, and C3-T2 fixation. In vitro flexibility tests were performed to determine the range of motion (ROM) of each group in flexion-extension (FE), lateral bending (LB), and axial rotation (AR), and to measure intradiscal pressure of the distal adjacent level (DAL).

RESULTS

In FE, selecting C7 as the LIV instead of crossing the CTJ resulted in the greatest increase in ROM (2.54°) and pressure (29.57 pound-force per square inch [psi]) at the DAL in the construct relative to the intact specimen. In LB, selecting T1 as the LIV resulted in the greatest increase in motion (0.78°) and the lowest increase in pressure (3.51 psi) at the DAL relative to intact spines. In AR, selecting T2 as the LIV resulted in the greatest increase in motion (0.20°) at the DAL, while selecting T1 as the LIV resulted in the greatest increase in pressure (8.28 psi) in constructs relative to intact specimens. Although these trends did not reach statistical significance, the observed differences were most apparent in FE, where crossing the CTJ resulted in less motion and lower intradiscal pressures at the DAL.

CONCLUSIONS

The present biomechanical cadaveric study demonstrated that a cervical posterior fixation construct with its LIV crossing the CTJ produces less stress in its distal adjacent discs compared with constructs with C7 as the LIV. Future clinical testing is necessary to determine the impact of this finding on patient outcomes.

Comparison of posterior muscle-preserving selective laminectomy and laminectomy with fusion for treating cervical spondylotic myelopathy: study protocol for a randomized controlled trial

BACKGROUND

Cervical spondylotic myelopathy (CSM) is the predominant cause of spinal cord dysfunction in the elderly. The patients are often frail and susceptible to complications. Posterior surgical techniques involving non-fusion are complicated by postlaminectomy kyphosis and instrumented fusion techniques by distal junction kyphosis, pseudarthrosis, or implant failure. The optimal surgical approach is still a matter of controversy. Since anterior and posterior fusion techniques have been compared without presenting any superiority, the objective of this study is to compare stand-alone laminectomy with laminectomy and fusion to determine which treatment has the lowest frequency of reoperations.

METHODS

This is a multicenter randomized, controlled, parallel-group non-inferiority trial. A total of 300 adult patients are allocated in a ratio of 1:1. The primary endpoint is reoperation for any reason at 5 years of follow-up. Sample size and power calculation were performed by estimating the reoperation rate after laminectomy to 3.5% and after laminectomy with fusion to 7.4% based on the data from the Swedish spine registry (Swespine) on patients with CSM. Secondary outcomes are the patient-derived Japanese Orthopaedic Association (P-mJOA) score, Neck Disability Index (NDI), European Quality of Life Five Dimensions (EQ-5D), Numeric Rating Scale (NRS) for neck and arm pain, Hospital Anxiety and Depression Scale (HADS), development of kyphosis measured as the cervical sagittal vertical axis (cSVA), and death. Clinical and radiological follow-up is performed at 3, 12, 24, and 60 months after surgery. The main inclusion criterium is 1-4 levels of CSM in the subaxial spine, C3-C7. The REDcap software will be used for safe data management. Data will be analyzed according to the modified intention to treat (mITT) population, defined as randomized patients who are still alive without having emigrated or left the study after 2 and 5 years.

DISCUSSION

This will be the first randomized controlled trial comparing two of the most common surgical treatments for CSM: the posterior muscle-preserving selective laminectomy and posterior laminectomy with instrumented fusion. The results of the myelopathy randomized controlled (MyRanC) study will provide surgical treatment recommendations for CSM. This may result in improvements in surgical treatment and clinical practice regarding CSM.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04936074 . Registered on 23 June 2021.

Predictors for cervical kyphotic deformity following laminoplasty: a systematic review and meta-analysis

OBJECTIVE

Laminoplasty is a common treatment for cervical spondylotic myelopathy (CSM) and for ossification of the posterior longitudinal ligament (OPLL). However, approximately 21% of patients undergoing laminoplasty develop cervical kyphotic deformity (KD). Because of the high prevalence rate of KD, several studies have sought to identify predictors for this complication, but the findings remain highly inconsistent. Therefore, the authors performed a systematic review and meta-analysis to establish reliable preoperative predictors of KD.

METHODS

PubMed, Scopus, and Web of Science databases were used to systematically extract potential references. The first phase of screening required the studies to be written in the English language, involve patients treated for CSM and/or OPLL via laminoplasty, and report postoperative cervical KD. The second phase required the studies to provide more than 10 patients and include a control group. The mean difference (MD) and odds ratio (OR) were calculated for continuous and dichotomous parameters. Study quality was evaluated using the Newcastle-Ottawa Scale. CSM and OPLL patients were further assessed by performing subgroup analyses.

RESULTS

Thirteen studies comprising patients who developed cervical KD (n = 296) and no KD (n = 1254) after receiving cervical laminoplasty for CSM or OPLL were included in the meta-analysis. All studies were retrospective cohorts and were rated as high quality. In the combined univariate analysis of CSM and OPLL patients undergoing laminoplasty, statistically significant predictors for postoperative KD included age (MD 2.22, 95% CI 0.16-4.27, p = 0.03), preoperative BMI (MD 0.85, 95% CI 0.06-1.63, p = 0.04), preoperative C2-7 range of flexion (MD 10.42, 95% Cl 4.24-16.59, p = 0.0009), preoperative C2-7 range of extension (MD -4.59, 95% CI -6.34 to -2.83, p < 0.00001), and preoperative center of gravity of the head to the C7 sagittal vertical axis (MD 26.83, 95% CI 9.13-44.52, p = 0.003). Additionally, among CSM patients, males were identified as having a greater risk for postoperative KD (OR 1.73, 95% CI 1.02-2.93, p = 0.04).

CONCLUSIONS

The findings from this study currently provide the largest and most reliable review on preoperative predictors for cervical KD after laminoplasty. Given that several of the included studies identified optimal cutoff points for the variables that are significantly associated with KD, further investigation into the development of a preoperative risk scoring system that can accurately predict KD in the clinical setting is encouraged. PROSPERO registration no.: CRD42022299795 (https://www.crd.york.ac.uk/PROSPERO/).

Cervical microendoscopic laminoplasty-induced clinical resolution of disc herniation in patients with single- to three-level myelopathy

This study aimed to explore the effects on resorption of cervical disc herniation (CDH) and clinical outcomes of surgery. Cervical microendoscopic laminoplasty (CMEL), which is commonly preferable to anterior corpectomy and fusion, was applied to patients with 1- to 3-level degenerative cervical myelopathy (DCM). DCM patients with 1-3 levels DCM underwent either conservation treatment or CMEL. In conservation-treated patients (53 cases), CDH volume remained unchanged with no improvement in JOA and VAS scores. Conversely, 63 patients with 1-3 levels DCM were prospectively enrolled and exhibited a profound decrease in CDH volume: 89.1% of CDHs (123/138) regressed over 10%, 64.5% of CDHs (89/138) regressed over 25%, while 27.5% and 6.5% of CDHs (38/138 and 9/138) largely regressed over 50% and 75%, respectively. Meanwhile, the JOA and VAS scores were improved in different ways. Intriguingly, CDH volume changes correlated significantly with elevations in JOA scores, indicating an association of clinical CDH resolution with neurological recovery. We showed that CMEL induced clinically related diminishment of CDH and alleviation of clinical symptoms in patients with 1- to 3-level myelopathy and that it could help avoid anterior dissection of the disc to some extent.

Evaluating a paradigm shift from anterior decompression and fusion to muscle-preserving selective laminectomy: a single-center study of degenerative cervical myelopathy

OBJECTIVE

Muscle-preserving selective laminectomy (SL) is an alternative to conventional decompression surgery in patients with degenerative cervical myelopathy (DCM). It is less invasive, preserves the extensor musculature, and maintains the range of motion of the cervical spine. Therefore, the preferred treatment for DCM at the authors' institution has changed from anterior decompression and fusion (ADF), including anterior cervical discectomy and fusion (ACDF) and anterior cervical corpectomy and fusion (ACCF), toward SL. The aim of this study was to evaluate surgical outcomes before and after this paradigm shift with patient-reported outcome measures (PROMs), complications, reoperations, and cost-effectiveness.

METHODS

This study was a retrospective register-based cohort study. All patients with DCM who underwent ADF or SL at the authors' institution from 2008 to 2019 were reviewed. Using ANCOVA, changes in PROMs from baseline to the 2-year follow-up were compared between the two groups, adjusting for clinicodemographic parameters, baseline PROMs, number of decompressed levels, and MRI measurements (C2-7 Cobb angle, C2-7 sagittal vertical axis [SVA], and modified K-line interval [mK-line INT]). The PROMs, including the European Myelopathy Score (EMS), the Neck Disability Index (NDI), and the EQ-5D, were collected from the national Swedish Spine Register. Complications, reoperations, and in-hospital treatment costs were also compared between the two groups.

RESULTS

Ninety patients (mean age 60.7 years, 51 men [57%]) were included in the ADF group and 63 patients (mean age 68.8 years, 41 men [65%]) in the SL group. The ADF and SL groups had similar PROMs at baseline. The preoperative MR images showed similar C2-7 Cobb angles (10.7° [ADF] vs 14.1° [SL], p = 0.12) and mK-line INTs (4.08 vs 4.88 mm, p = 0.07), but different C2-7 SVA values (16.2 vs 19.3 mm, p = 0.04). The comparison of ANCOVA-adjusted mean changes in PROMs from baseline to the 2-year follow-up presented no significant differences between the groups (EMS, p = 0.901; NDI, p = 0.639; EQ-5D, p = 0.378; and EQ-5D health, p = 0.418). The overall complication rate was twice as high in the ADF group (22.2% vs 9.5%, p = 0.049), while the reoperation rate was comparable (16.7% vs 7.9%, p = 0.146). The average in-hospital treatment cost per patient was $6617 (USD) for SL, $7046 for ACDF, and $12,000 for ACCF.

CONCLUSIONS

SL provides similar PROMs after 2 years, a significantly lower complication rate, and better cost-effectiveness compared with ADF.

Comparison of anterior cervical discectomy and fusion versus artificial disc replacement for cervical spondylotic myelopathy: a meta-analysis

OBJECTIVE

Anterior cervical discectomy and fusion (ACDF) has long been regarded as a gold standard in the treatment of cervical myelopathy. Subsequently, cervical artificial disc replacement (c-ADR) was developed and provides the advantage of motion preservation at the level of the intervertebral disc surgical site, which may also reduce stress at adjacent levels. The goal of this study was to compare clinical and functional outcomes in patients undergoing ACDF with those in patients undergoing c-ADR for cervical spondylotic myelopathy (CSM).

METHODS

A systematic literature review and meta-analysis were performed using the Embase, PubMed, and Cochrane Central Register of Controlled Trials databases from database inception to November 21, 2021. The authors compared Neck Disability Index (NDI), SF-36, and Japanese Orthopaedic Association (JOA) scores; complication rates; and reoperation rates for these two surgical procedures in CSM patients. The Mantel-Haenszel method and variance-weighted means were used to analyze outcomes after identifying articles that met study inclusion criteria.

RESULTS

More surgical time was consumed in the c-ADR surgery (p = 0.04). Shorter hospital stays were noted in patients who had undergone c-ADR (p = 0.04). Patients who had undergone c-ADR tended to have better NDI scores (p = 0.02) and SF-36 scores (p = 0.001). Comparable outcomes in terms of JOA scores (p = 0.24) and neurological success rate (p = 0.12) were noted after the surgery. There was no significant between-group difference in the overall complication rates (c-ADR: 18% vs ACDF: 25%, p = 0.17). However, patients in the ACDF group had a higher reoperation rate than patients in the c-ADR group (4.6% vs 1.5%, p = 0.02).

CONCLUSIONS

At the midterm follow-up after treatment of CSM, better functional outcomes as reflected by NDI and SF-36 scores were noted in the c-ADR group than those in the ACDF group. c-ADR had the advantage of retaining range of motion at the level of the intervertebral disc surgical site without causing more complications. A large sample size with long-term follow-up studies may be required to confirm these findings in the future.

A randomized controlled study of two different fixations in anterior cervical discectomy of multilevel cervical spondylotic myelopathy

Background: To compare the efficacy of anterior cervical discectomy and hybrid fusion (ACDHF) with short-segment plate plus self-locking, stand-alone intervertebral cages versus traditional anterior cervical discectomy and fusion (ACDF) with long-segment plate for multilevel cervical spondylotic myelopathy (MCSM). Methods: All the patients were randomly divided into two groups. 30 cases underwent ACDHF with short-segment plate and self-locking stand-alone cages (hybrid group), while the other 30 cases received ACDF with long-segment plate (control group). In patients meeting the inclusion and exclusion criteria, operation time, blood loss, postoperative drainage volume, length of stay (LOS), visual analogue scale for neck pain (VASNP) scores, Japanese Orthopaedic Association (JOA) score, and the cervical lordosis before and after the operation (5 days, 3, 6, 12 months after operation and final follow-up) were evaluated. The postoperative complications were analyzed as well. Results: All operations were performed uneventfully with followed-up. Compared with ACDF, ACDHF showed a shorter operation time, less intraoperative blood loss and postoperative drainage (p < 0.05). There were no significant difference in LOS between two groups (p ˃ 0.05). Both approaches significantly improved the JOA scores, VASNP scores and the cervical lordosis (p < 0.05). Based on Bazaz grading system, hybrid group had a lower incidence of dysphagia than control group in follow-up periods of 5 days, 3 and 6 months (p < 0.05). Conclusion: ACDF and ACDHF are both effective methods of restoring cervical lordosis following MCSM, but hybrid surgery minimizes intraoperative injury and postoperative dysphagia, making it a viable treatment option for the disorder.

A Comparison of Various Surgical Treatments for Degenerative Cervical Myelopathy: A Propensity Score Matched Analysis

STUDY DESIGN

Retrospective Cohort.

OBJECTIVE

To compare the short-term outcomes for Laminoplasty, Laminectomy/fusion, and ACDF.

METHODS

We utilized a prospectively-collected, multi-center national database with a propensity score matching algorithm to compare the short-term outcomes for laminoplasty, laminectomy/fusion, and multi-level (>3) ACDF (with and without corpectomy). Bivariate analyses involved both chi-square/fisher exact test and t-test/ANOVA on perioperative factors. Multivariate analyses were performed to determined independent risk factors for short term outcomes.

RESULTS

546 patients remained after propensity score matching, with 182 patients in each cohort. ACDF required the longest operative time 188 ± 79 versus laminectomy/fusion (169 ± 75, p = 0.017), and laminoplasty (167 ± 66, p = 0.004). ACDF required the shortest hospital stay (LOS ≥ 2: ACDF 56.6%, laminoplasty 89.6%, laminectomy/fusion 93.4%, p < 0.05). ACDF had lower overall complications (ACDF 3.9%, laminoplasty 7.7%, laminectomy/fusion 11.5%, p < 0.05), mortality (ACDF 0%, laminoplasty 0.55%, laminectomy/fusion 2.2%, p < 0.05), and unplanned readmissions (ACDF 4.4%, laminoplasty 4.4%, laminectomy/fusion 9.9%, p < 0.05). No significant differences were seen in the other outcomes including DVT/PT, acute renal failure, UTI, stroke, cardiac complications, or sepsis. In the multivariate analysis, laminectomy/fusion (OR 17, reference: ACDF) and laminoplasty (OR10, reference: ACDF) were strong independent risk factors for LOS ≥ 2 days. Laminectomy/fusion (OR 3.2, reference: ACDF) was an independent predictor for any adverse events 30-days after surgery.

CONCLUSIONS

Laminectomy/fusion carries the highest risk for morbidity, mortality, and unplanned readmissions in the short-term postoperative period. Laminoplasty and ACDF cases carry similar short-term complications risks. ACDF is significantly associated with the longest operative duration and shortest LOS without an increase in individual or overall complications, readmissions, or reoperations.

Differences in Patient-Reported Outcomes Between Anterior and Posterior Approaches for Treatment of Cervical Spondylotic Myelopathy: A Quality Outcomes Database Analysis

OBJECTIVE

Surgery for cervical spondylotic myelopathy (CSM) may use anterior or posterior approaches. Our objective was to compare baseline differences and validated postoperative patient-reported outcome measures between anterior and posterior approaches.

METHODS

The NeuroPoint Quality Outcomes Database was queried retrospectively to identify patients with symptomatic CSM treated at 14 high-volume sites. Demographic, comorbidity, socioeconomic, and outcome measures were compared between treatment groups at baseline and 3 and 12 months postoperatively.

RESULTS

Of the 1151 patients with CSM in the cervical registry, 791 (68.7%) underwent anterior surgery and 360 (31.3%) underwent posterior surgery. Significant baseline differences were observed in age, comorbidities, myelopathy severity, unemployment, and length of hospital stay. After adjusting for these differences, anterior surgery patients had significantly lower Neck Disability Index score (NDI) and a higher proportion reaching a minimal clinically important difference (MCID) in NDI (P = 0.005 at 3 months; P = 0.003 at 12 months). Although modified Japanese Orthopaedic Association scores were lower in anterior surgery patients at 3 and 12 months (P < 0.001 and P = 0.022, respectively), no differences were seen in MCID or change from baseline. Greater EuroQol-5D improvement at 3 months after anterior versus posterior surgery (P = 0.024) was not sustained at 12 months and was insignificant on multivariate analysis.

CONCLUSIONS

In the largest analysis to date of CSM surgery data, significant baseline differences existed for patients undergoing anterior versus posterior surgery for CSM. After adjusting for these differences, patients undergoing anterior surgery were more likely to achieve clinically significant improvement in NDI at short- and long-term follow-up.

Volumetric Changes in Cervical Disc Herniation: Comparison of Cervical Expansive Open-door Laminoplasty and Cervical Microendoscopic Laminoplasty

STUDY DESIGN

Retrospective study on 185 patients with 490 cervical disc herniation (CDH).

OBJECTIVE

The aim of this study was to compare the changes in volumes of CDH in patients with degenerative cervical myelopathy (DCM) surgically treated by expansive open-door laminoplasty (EOLP) or cervical microendoscopic laminoplasty (CMEL).

SUMMARY OF BACKGROUND DATA

Spontaneous resorption of CDH was shown in patients with DCM after conservation treatment, but very few in surgically treated patients. Our previous study identified the clinical efficiency of CMEL to treat DCM but how CDH sized postoperatively, as well as comparing to EOLP, was unknown.

METHODS

Consecutive patients with DCM from December 2015 to December 2019, who underwent MRI evaluation, receiving CMEL or EOLP, and repeat MRI in follow-up were included. The volume of CDH were monitored using the picture archiving and communication system, further calculating the incidence of CDH with volume regression and the percentage changes of CDH volume. The correlations of possible determines with CDH volume changes were analyzed by Spearman rank correlation coefficient.

RESULTS

A total of 89 patients (215 CDHs, EOLP-group) and 96 patients (275 CDHs, CMEL-group) was surveyed, respectively. Resultantly, volume of CDH was decreased postoperatively in both EOLP and CMEL cases. But this CDH volume regression was more profound in CMEL groups (incidence of 81.2% from 223/275, median volume change ratio of -26.7%, occurring from 1 month after CMEL), statistically different from EOLP group (50.2% from 108/215, median volume change ratio of -5.4%, none-appearance within 1 month). Patients information as sex, age, and follow-up time, not CDH significant, was significantly correlated with CDH volume changes.

CONCLUSION

Patients who underwent CMEL developed a postoperative reduction of CDH volume, with more popularity, greater degree and earlier-staged than EOLP-patients. Young females with longer follow-up time were more likely occur.Level of Evidence: 4.

Cervical Myelopathy: An Update on Posterior Decompression

STUDY DESIGN

This was a narrative review.

OBJECTIVE

The aim was to discuss current methods and review updated outcome studies regarding posterior decompression in the management of cervical myelopathy.

SUMMARY OF BACKGROUND DATA

Progressive myelopathy in the cervical segments is an indication for urgent surgical management. Although nonoperative treatment is an option in mild to moderate cases, the majority of patients will experience deterioration in neurological function requiring surgical decompression.

METHODS

A review of the literature was performed using PubMed to provide updated information regarding posterior cervical decompression in the management of myelopathy.

RESULTS

There are numerous studies comparing outcome data between cervical laminectomy and fusion with laminoplasty. While each technique has advantages and disadvantages, both provide adequate decompression and good long-term outcomes in patients meeting appropriate criteria.

CONCLUSIONS

Posterior decompression is an important approach for spine surgeons to have in their toolkits when treating cervical myelopathy.

Anterior vs Posterior Approach in Multilevel Cervical Spondylotic Myelopathy: A Nationwide Propensity-Matched Analysis of Complications, Outcomes, and Narcotic Use

BACKGROUND

There is unclear evidence regarding the optimal surgical approach for multilevel cervical spondylotic myelopathy (CSM). The objective of this study was to compare complications, outcomes, and narcotic use in anterior discectomy and fusion (ACDF) vs posterior decompression and fusion (PCDF) in CSM patients.

STUDY DESIGN

Registry-based retrospective cohort analysis.

METHODS

Patients undergoing 3-level ACDF or PCDF for CSM between 2007 and 2017 were identified from the Humana Claims Database using relevant procedure codes. Propensity score-matched groups were compared in regards to complications, outcomes, and narcotic use.

RESULTS

Propensity score matching generated equal cohorts of 6124 patients. The posterior fusion group had a higher rate of urinary tract infection (OR 2.47, P < 0.0001), deep vein thrombosis (OR 1.90, P < 0.0001), and pulmonary embolism (OR 1.75, P < 0.0001). In regards to 30-day outcomes, the posterior approach demonstrated higher rates of stroke (OR 1.68, P < 0.0001), wound dehiscence (OR 5.59, P < 0.0001), Surgical site infection (SSI) (OR 4.76, P < 0.0001), wound revision surgery (OR 3.02, P < 0.0001), and all-cause readmission (OR 2.01, P < 0.0001). One-year outcomes revealed higher rates of pseudarthrosis (4.7% vs 2.0%, OR 2.43, P < 0.0001) and revision or extension surgery (OR 2.33, P < 0.0001) in the posterior fusion cohort. These patients also demonstrated significantly higher mean morphine milligram equivalent used at 30 days (OR 1.19, P < 0.0001), as well as 60 (OR 1.20, P < 0.0001), 90 (OR 1.21, P < 0.0001), and 120 (OR 1.21, P < 0.0001) days.

CONCLUSIONS

This nationwide propensity-matched analysis of multilevel CSM patients found the posterior approach to be associated with increased rates of inpatient complications, wound complications, 30-day readmission, 1-year pseudarthrosis, and 1-year revision or extension surgery. These patients also demonstrated higher levels of narcotic use up to 120 days after surgery.

CLINICAL RELEVANCE

The posterior approach for treatment of CSM may be associated with increased rates of short- and long-term complications in addition to increased narcotic consumption in comparison to the anterior approach.

Incidence of Arterial Hypertension in People With Periodontitis and Characterization of the Oral and Subgingival Microbiome: A Study Protocol

Cardiovascular diseases are the leading cause of morbidity and mortality worldwide. High blood pressure in particular, continues to increase throughout the global population at an increasingly fast pace. The relationship between arterial hypertension and periodontitis has been recently discussed in the context of its origins and implications. Particularly relevant is the role of the periodontal microbiome linked to persistent local and systemic inflammation, along with other risk factors and social determinants of health. The present protocol will investigate/assess the association between periodontal disease and its microbiome on the onset of hypertension, within a cohort from Mexico City. One thousand two hundred twelve participants will be studied during a 60-month period. Studies will include analysis of periodontal conditions, sampling and sequencing of the salivary and subgingival microbiome, interviews on nutritional and lifestyle habits, social determinants of health, blood pressure and anthropometric measurements. Statistical associations and several classic epidemiology and machine learning approaches will be performed to analyze the data. Implications for the generation of public policy—by early public health interventions or epidemiological surveillance approaches—and for the population empowerment—via the establishment of primary prevention recommendations, highlighting the relationship between oral and cardiovascular health—will be considered. This latter set of interventions will be supported by a carefully planned science communication and health promotion strategy. This study has been registered and approved by the Research and Ethics Committee of the School of Dentistry, Universidad Nacional Autónoma de México (CIE/0308/05/2019) and the National Institute of Genomic Medicine (CEI/2020/12). The umbrella cohort was approved by the Institutional Bioethics Committee of the National Institute of Cardiology-Ignacio Chavez (INC-ICh) under code 13-802.

ACDF and posterior spinal fusion revision for posterior nonunion with deformity, myelopathy, and osteoporosis in an 87-year-old: A case report and literature review

Introduction

Cervical spondylotic myelopathy (CSM) is a spinal degenerative disorder that can ultimately lead to compression of the vertebral column with neurological sequelae. Although CSM is the most common spine pathology in the elderly American population, it remains a challenging disorder to treat among older patients.

Case presentation

We report an 86 year old female patient with CSM with a history of posterior cervical fusion attempt on C3-C6 that progressed to C3-C6 nonunion with loose instrumentation. The patient had severe osteoporosis. With these indications, the patient underwent a combined anterior-posterior decompression and fusion (CAPDF) consisting of anterior cervical discectomy and fusion (ACDF) of the C3-C5, corpectomy of C6 and C7 with off FDA label use of polymethyl methacrylate augmentation (PMMA) fixation of T1 screws anteriorly for C3-T1 plate fixation and second stage instrumented posterior spinal fusion (PSF) of C3-T3. The patient had a successful fusion and reduction of her cervical spine pain with preservation of her neurological status.

Discussion

We report this case of multi-stage combined anterior and posterior fusion as a corrective measure for pseudarthrosis of a prior posterior cervical spinal fusion attempt.

Conclusion

In the event of posterior spinal fusion instrumentation failure in patients with severe osteoporosis, combined multi-stage anterior-posterior fusion is a viable corrective intervention in octogenarians. This case also illustrated the utility of using PMMA for anterior cervical plate and screw stabilization in osteoporotic bone. The authors are not aware of the prior use of PMMA for screw fixation augmentation in the anterior cervical spine.

•

Combined anterior-posterior cervical fusion for cervical spondylotic myelopathy and pseudarthrosis of prior intended fusion.

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Polymethylmethacrylate (PMMA) demonstrated as safe and effective for screw purchase augmentation in anterior cervical spine

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Multi stage spinal fusion to limit prolonged one-stage anesthesia identified to be safe and effective for this patient

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Management of cervical fusion pseudarthrosis in the setting of osteoporosis in the elderly

Laminectomy alone versus laminectomy with fusion for degenerative cervical myelopathy: a long-term study of a national cohort

PURPOSE

To compare patient-reported 5-year clinical outcomes between laminectomy alone versus laminectomy with instrumented fusion in patients with degenerative cervical myelopathy in a population-based cohort.

METHODS

All patients in the national Swedish Spine Register (Swespine) from January 2006 until March 2019, with degenerative cervical myelopathy, were assessed. Multiple imputation and propensity score matching based on clinicodemographic and radiographic parameters were used to compare patients treated with laminectomy alone with patients treated with laminectomy plus posterior-lateral instrumented fusion. The primary outcome measure was the European Myelopathy Score, a validated patient-reported outcome measure. The scale ranges from 5 to 18, with lower scores reflecting more severe myelopathy.

RESULTS

Among 967 eligible patients, 717 (74%) patients were included. Laminectomy alone was performed on 412 patients (mean age 68 years; 149 women [36%]), whereas instrumented fusion was added for 305 patients (mean age 68 years; 119 women [39%]). After imputation, the propensity for smoking, worse myelopathy scores, spondylolisthesis, and kyphosis was slightly higher in the fusion group. After imputation and propensity score matching, there were on average 212 pairs patients with a 5-year follow-up in each group. There were no important differences in patient-reported clinical outcomes between the methods after 5 years. Due to longer hospitalization times and implant-related costs, the mean cost increase per instrumented patient was approximately $4700 US.

CONCLUSIONS

Instrumented fusions generated higher costs and were not associated with superior long-term clinical outcomes. These findings are based on a national cohort and can thus be regarded as generalizable.

Perioperative Complications in Posterior Surgeries for Cervical Ossification of the Posterior Longitudinal Ligament: A Prospective Nationwide Investigation

STUDY DESIGN

This was a prospective multicenter study.

OBJECTIVE

The aim of this study was to investigate the perioperative complications of posterior surgeries for the treatment of cervical ossification of the posterior longitudinal ligament (OPLL).

SUMMARY OF BACKGROUND DATA

Surgical treatment for cervical OPLL has a high risk of various complications. Laminoplasty (LAMP) and posterior decompression and instrumented fusion (PDF) are effective for multilevel cervical OPLL; however, few studies have focused on the surgical complications of these 2 procedures.

MATERIALS AND METHODS

We prospectively included 380 patients undergoing posterior surgeries for cervical OPLL (LAMP: 270 patients, PDF: 110 patients), and investigated the systemic and local complications, including neurological complications. We further evaluated risk factors related to the neurological complications.

RESULTS

Motor palsy was found in 40 patients (10.5%), and motor palsy in the upper extremity was most frequent (8.9%), especially in patients who received PDF (14.5%). Motor palsies involving the lower extremities was found in 6 patients (1.6%). Regarding local complications, dural tears (3.9%) and surgical site infections (2.6%) were common. In the univariate analysis, body mass index, preoperative cervical alignment, fusion surgery, and the number of operated segments were the factors related to motor palsy. Multivariate analysis revealed that fusion surgery and a small preoperative C2-C7 angle were the independent factors related to motor palsy. Motor palsy involving the lower extremities tended to be found at early time points after the surgery, and all the patients fully recovered. Motor palsy in the upper extremities occurred in a delayed manner, and 68.8% of patients with PDF showed good recovery, whereas 81.3% of patients with LAMP showed good recovery.

CONCLUSIONS

In posterior surgeries for cervical OPLL, segmental motor palsy in the upper extremity was most frequently observed, especially in patients who received PDF. Fusion and a small preoperative C2-C7 angle were the independent risk factors for motor palsy.

LEVEL OF EVIDENCE

Level III.

Degenerative Cervical Myelopathy: Towards a Personalized Approach

Degenerative cervical myelopathy (DCM) is a recently coined term encompassing a variety of age-related and genetically associated pathologies, including cervical spondylotic myelopathy, degenerative disc disease, and ligamentous aberrations such as ossification of the posterior longitudinal ligament. All of these pathologies produce chronic compression of the spinal cord causing a clinical syndrome characterized by decreased hand dexterity, gait imbalance, and potential genitourinary or sensorimotor disturbances. Substantial variability in the underlying etiology of DCM and its natural history has generated heterogeneity in practice patterns. Ongoing debates in DCM management most commonly center around clinical decision-making, timing of intervention, and the ideal surgical approach. Pivotal basic science studies during the past two decades have deepened our understanding of the pathophysiologic mechanisms surrounding DCM. Growing knowledge of the key pathophysiologic processes will help us tailor personalized approaches in an increasingly heterogeneous patient population. This article focuses on summarizing the most exciting approaches in personalizing DCM patient treatments including biomarkers, factors affecting clinical decision-making, and choice of the optimal surgical approach. Throughout we provide a concise review on the conditions encompassing DCM and discuss the underlying pathophysiology of chronic spinal cord compression. We also provide an overview on clinical-radiologic diagnostic modalities as well as operative and nonoperative treatment strategies, thereby addressing knowledge gaps and controversies in the field of DCM.

Comparison of Lateral Lumbar Interbody Fusion and Posterior Lumbar Interbody Fusion as Corrective Surgery for Patients with Adult Spinal Deformity-A Propensity Score Matching Analysis

Lateral lumbar interbody fusion (LLIF) is increasingly performed as corrective surgery for patients with adult spinal deformity (ASD). This paper compares the surgical results of LLIF and conventional posterior lumbar interbody fusion (PLIF)/transforaminal lumbar interbody fusion (TLIF) in ASD using a propensity score matching analysis. We retrospectively reviewed patients with ASD who received LLIF and PLIF/TLIF, and investigated patients’ backgrounds, radiographic parameters, and complications. The propensity scores were calculated from patients’ characteristics, including radiographic parameters and preoperative comorbidities, and one–to-one matching was performed. Propensity score matching produced 21 matched pairs of patients who underwent LLIF and PLIF/TLIF. All radiographic parameters significantly improved in both groups at the final follow-up compared with those of the preoperative period. The comparison between both groups demonstrated no significant difference in terms of postoperative pelvic tilt, lumbar lordosis (LL), or pelvic incidence–LL at the final follow-up. However, the sagittal vertical axis tended to be smaller in the LLIF at the final follow-up. Overall, perioperative and late complications were comparable in both procedures. However, LLIF procedures demonstrated significantly less intraoperative blood loss and a smaller incidence of postoperative epidural hematoma compared with PLIF/TLIF procedures in patients with ASD.

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.

Perioperative major neurologic deficits as a complication of spine surgery

STUDY DESIGN

Retrospective review of spine surgery patients with new major neurologic complication.

OBJECTIVE

To define the causes and severity of new neurologic damage to the spinal cord or cauda equina caused by spinal surgery.

MATERIALS AND METHODS

Consult records were reviewed for all postoperative spine surgery patients referred to a tertiary spinal cord injury rehabilitation center over a 12-year period. Any patients with a new perioperative surgery-related decrement in American Spinal Injury Association (ASIA) Impairment Scale (AIS), loss of bowel or bladder function, or loss of ability to ambulate were examined and final 1-year gaps for neurologic loss reported.

RESULTS

64 patients had a new perioperative major neurologic event with: 41% thoracic, 39% cervical, and 20% lumbar; 61% intraoperative, 31% in the immediate 2-week postoperative period, 8% unknown. Chronic myelopathy (44%) was the most common indication. The causes of neurologic injury were postoperative fluid collection (25%), malposition of instrumentation (14%), traumatic decompression (14%), cord infarct (11%), deformity correction (2%), and unknown (34%). Overall, 87% lost the ability to ambulate and 66% lost volitional bowel-bladder control. AIS decrement and loss of ambulation and bowel-bladder function did not differ statistically significantly by surgical indication. However, among the main root causes, traumatic decompressions and cord infarcts had significantly worse neurologic deterioration than fluid collections or malposition of instrumentation.

CONCLUSION

The relative rate of major neurologic injury in spine surgery is higher in thoracic and cervical cases at spinal cord levels, especially when done for myelopathy, even though lumbar surgeries are most common. The most common causes of neurologic injury were potentially avoidable postoperative fluid collections, malposition of instrumentation, and traumatic decompression.

Subaxial Spine Fractures: A Comparison of Patient-reported Outcomes and Complications Between Anterior and Posterior Surgery

STUDY DESIGN

Observational study on prospectively collected data.

OBJECTIVES

The aim of this study was to compare long-term patient-reported outcomes and complications after anterior or posterior cervical spine surgery for subaxial fractures.

SUMMARY OF BACKGROUND DATA

There is no consensus in the literature regarding the optimal surgical approach when treating spine fractures in the subaxial region.

METHODS

A total of 200 individuals who had been treated with either anterior or posterior surgery due to a subaxial single segment, or single vertebra, injury between 2006 and 2016 and had at least 1 year follow-up were identified in the Swedish Spine register. Cases were matched 1:1 for age (±5 years). Outcomes were Neck Disability Index (NDI) and EQ-5D-3L, and reoperations, mortality, and surgeon- and patient-reported wound complications within 90 days. t Tests and χ2 tests were used statistical comparisons.

RESULTS

At follow-up, NDI was 23 (21) in the anterior group and 29 (21) in the posterior group (P = 0.07). EQ-5D-3L index was 0.62 (0.37) in the anterior group and 0.54 (0.39) in the posterior group (P = 0.13). Patient satisfaction was higher in the anterior group (89% vs. 73%, P = 0.03). No deaths occurred within the first 90 days after surgery, six individuals in the anterior group and three individuals in the posterior group were reoperated (P = 0.31), and five individuals in the anterior group and 24 in the posterior group suffered a wound infection (P < 0.001).

CONCLUSION

Anterior surgery and posterior surgery were associated with similar neck disability and general quality of life at follow-up, whereas anterior surgery was associated with higher patient satisfaction and lower infection rates.Level of Evidence: 3.

A Bibliometric Analysis and Visualization of Current Research Trends in the Treatment of Cervical Spondylotic Myelopathy

STUDY DESIGN

Bibliometric analysis.

OBJECTIVE

Cervical spondylotic myelopathy (CSM) has become the most common cause of spinal cord dysfunction. Many topics of CSM still remain controversial. This study aimed to illustrate the overall knowledge structure and development trends of CSM.

METHODS

Research data sets were acquired from the Web of Science database and the time span was defined as "2000 to 2019." VOS viewer and Citespace software was used to analyze the data and generate visualization knowledge maps. Annual trends of publications, distribution, H-index status, co-authorship status, and research hotspots were analyzed.

RESULTS

A total of 2367 publications met the requirement. The largest number of articles was from the United States, followed by Japan, China, Canada, and India. The highest H-index was found for articles from the United States. The highest number of articles was published in Spine. The cooperation between the countries, institutes, and authors were relatively weak. Cervical sagittal alignment, predictive factor, diffusion tensor imaging, and the natural history of CSM may become a frontier in this research field.

CONCLUSION

The number of publications showed an upward trend with a stable rise. Most of the publications are limited to a few countries and institutions with relatively weak interaction. The United States, Canada, Japan, China, and India have made significant contributions to the field of CSM. The United States is the country with the highest productivity, not only in quality but also in quantity. Cervical sagittal alignment, predictive factor, diffusion tensor imaging, and the natural history of CSM are the research hotspots in the recent years.

Predictors associated with neurological recovery after anterior decompression with fusion for degenerative cervical myelopathy

BACKGROUND

Anterior decompression with fusion (ADF) has often been performed for degenerative cervical myelopathy (DCM) in patients with poor cervical spine alignment and/or anterior cord compression. We aimed to identify clinical and radiological predictors associated with neurological recovery after ADF.

METHODS

This post-hoc analysis from a prospective multicenter study included patients who were scheduled for ADF for DCM. The patients who received other surgeries (laminoplasty, posterior decompression and fusion) were excluded. The associations between baseline clinical and radiographic variables (age, sex, body mass index, etiology, cervical lordosis, range of motion, C7 slope, C2-7 sagittal vertical axis [SVA], thoracic kyphosis [TK], lumbar lordosis, sacral slope, SVA, pelvic tilt, T1 pelvic angle [TPA], the Japanese Orthopedic Association score for the assessment of cervical myelopathy [C-JOA], European Quality of Life Five Dimensions Scale [EQ-5D], Neck Disability Index [NDI], Physical Component Summary of the SF-36 [PCS], and Mental Component Summary of the SF-36) and the recovery rates as the outcome variables were investigated in the univariate regression analysis. Then, the independent predictors for increased recovery rates were evaluated using a stepwise multiple regression analysis.

RESULTS

In total, 37 patients completed the 1 year follow-up. The recovery rate was significantly correlated with SVA (p = 0.001) and TPA (p = 0.03). Univariate regression analyses showed that age (Regression coefficient = - 0.92, p = 0.049), SVA (Regression coefficient  = - 0.57, p = 0.004) and PCS (Regression coefficient = 0.80, p = 0.03) score were significantly associated with recovery rate. Then, a stepwise multiple regression analysis identified the independent predictors of recovery rate after ADF as TK (p = 0.01), PCS (p = 0.03), and SVA (p = 0.03). According to this prediction model, the following equation was obtained: recovery rate = - 8.26 + 1.17 × (TK) - 0.45 × (SVA) + 0.85 × (PCS) (p = 0.002, R² = 0.44).

CONCLUSION

Patients with lower TK, lower PCS score, and higher SVA were more likely to have poor neurological recovery after ADF. Therefore, patients with DCM and these predictors who undergo ADF should be warned about poor recovery and be required to provide adequate informed consent.

Use of electromyography to predict likelihood of recovery following C5 palsy after posterior cervical spine surgery

BACKGROUND

C5 palsy affects approximately 5% to 10% of patients undergoing cervical spine surgery. It has a significant negative impact on patient quality-of-life outcomes and healthcare costs. Although >80% of patients improve, some are left with persistent, debilitating deficits. Our objective was to examine if electrodiagnostic testing could be used to successfully identify patients likely to experience complete, partial, and no recovery.

METHODS

Patients undergoing posterior cervical decompression and fusion at a single institution over a 10-year period were identified. Those experiencing postoperative C5 palsy were included. Outcomes examined included motor recovery of the affected deltoid as a function of time, and changes in electrodiagnostic testing as a function of time since injury. Electrodiagnostic testing included electromyography and was sub-analyzed by time of acquisition postinjury. Deltoid strength was graded on manual motor testing using the 5-point medical research council grading system.

RESULTS

Of 77 patients experiencing C5 palsy, 29 had postoperative electrodiagnostic testing. Patients experiencing complete recovery on average achieved functional (4/5) strength by 6-weeks post injury and 4+ per 5 strength by 6-months. Those experiencing partial recovery only achieved antigravity strength (3/5) by 6-weeks and low-function (4-/5) strength by 6-months. Electrodiagnostic testing performed 6-weeks to 6-months postinjury demonstrated that those experiencing complete recovery were more likely to have normal motor unit (MU) recruitment than those experiencing partial (p<.001) or no recovery (p=.008). The presence of ≥2+ fibrillation on tests acquired ≤6-weeks of injury identified patients unlikely to experience any recovery with a positive predictive value (PPV) of 88.9%. The presence of normal MU recruitment on tests acquired 6-weeks to 6-months postinjury identified patients likely to experience complete recovery with a PPV of 87.5%.

CONCLUSIONS

Electrodiagnostic testing may be a valuable means of differentiating between patients with C5 palsy likely to experience complete, partial, or no recovery. Testing between 6-weeks and 6-months post onset may aid in identifying those least likely to have a complete recovery. No MUs at 4 to 6-months, or reduced units with strength that is not improving, portends a poor long-term outcome. In this population, peripheral nerve transfers may be considered sooner.

Surgery for Degenerative Cervical Myelopathy: What Really Counts?

STUDY DESIGN

Retrospective study (data analysis).

OBJECTIVE

The purpose of this study was to assess the role of different factors on postoperative outcome of patients with degenerative cervical myelopathy (DCM).

SUMMARY OF BACKGROUND DATA

Ongoing degenerative changes of DCM lead to progressive neurological deficits. The optimal timing of surgical treatment is still unclear, especially in patients with mild DCM.

METHODS

Patients with DCM treated in our clinic between 2007 and 2016 were retrospectively analyzed. Pre- and postoperative neurological function was assessed by the modified Japanese Orthopaedic Association Score (mJOA Score) at different stages. The minimum clinically important difference (MCID) was used to evaluate the improvement after surgery. The comorbidities were recorded using the Charlson Comorbidity Index (CCI). Possible associations between age, sex, CCI, preoperative symptoms duration, high signal intensity (SI) on T2-weighted magnetic resonance imaging (MRI) with mJOA Score and MCID were analyzed using univariate analysis and multivariate regression models. Additionally, subgroup analysis was performed according to the severity of DCM (mild: mJOA Score ≥15 points; moderate: mJOA Score of 12-14 points; and severe: mJOA Score <12 points).

RESULTS

The mean age of the final cohort (n = 411) was 62.6 years (range: 31-96 years), 36.0% were females. High SI on T2-weighted MRI was detected in 60.3% of the cases. In the multivariate analysis, patients' age (P = 0.005), higher CCI (P = 0.001), and presence of high SI on T2-weighted MRI (P = 0.0005) were associated independently with lower pre- and postoperative mJOA Score and postoperative MCID. Subgroup analysis revealed age and high SI on T2-weighted MRI as predictors of pre- and postoperative mJOA. However, symptom duration did not influence neurological outcome according to the severity of DCM.

CONCLUSION

Surgery for DCM leads to significant functional improvement. However, better outcome was observed in younger individuals with lower CCI and absence of radiographic myelopathy signs. Therefore, DCM surgery, particularly before occurrence of high SI on MRI, seems to be essential for postoperative functional improvement regardless the above-mentioned confounders.Level of Evidence: 3.

Efficacy and Safety of Ultrasonic Bone Curette-assisted Dome-like Laminoplasty in the Treatment of Cervical Ossification of Longitudinal Ligament

Objective

To assess the efficacy and safety of ultrasonic bone curette‐assisted dome‐like laminoplasty in the treatment of ossification of longitudinal ligament (OPLL) involving C₂.

Methods

A total of 64 patients with OPLL involving C₂ level were enrolled. Thirty‐eight patients who underwent ultrasonic bone curette‐assisted dome‐like laminoplasty were defined as ultrasonic bone curette group (UBC), and 28 patients who underwent traditional high‐speed drill‐assisted dome‐like laminoplasty were defined as high‐speed drill group (HSD). Patient characteristics such as age, sex, body mass index (BMI), symptomatic duration, and other information like the type of OPLL, the time of surgery, blood loss, C₂–C₇ Cobb angle change and complications were all recorded and compared. The Japanese Orthopaedic Association (JOA) score, the nerve root functional improvement rate (IR), and the visual analogue scale (VAS) were used to assess neurological recovery and pain relief. The change of the distance between the apex of ossification and a continuous line connecting the anterior edges of the lamina was measured to assess the spinal expansion extent. The measured data were statistically processed and analyzed using SPSS 21.0 software, and the measurement data were expressed as mean ± SD.

Results

In ultrasonic bone curette (UBC) group and high‐speed drill group (HSD) group, the average time for laminoplasty was 52.3 ± 18.2 min and 76.0 ± 21.8 min and the mean bleeding loss volume was 155.5 ± 41.3 mL and 177.4 ± 54.7 mL, respectively, with a statistically significant difference between the groups. Both groups demonstrated a significant improvement in neurological function. However, the VAS score in UBC group was lower than in HSD group at the 6‐month follow‐up (P < 0.05), but there was no significant difference at 1‐year follow‐up. We found that the loss of lordosis was 1.5° ± 1.0° in UBC group, which is significantly lower than that of HSD group at 1‐year follow‐up (3.8° ± 1.2°, P < 0.05). According to the change of canal dimension, we found that the expansion extent of the spinal canal in UBC group was similar to that of HSD group (P > 0.05). Only one patient in the UBC group and five patients in the HSD group displayed cerebrospinal fluid (CSF) leakag.

Conclusions

With the use of ultrasonic bone curette in OPLL dome‐like decompression, the decompression surgery could be completed relatively safely and quickly. It effectively reduced the amount of intraoperative blood loss and complications, and had better initial recovery of neck pain.

Surgical decision-making for ossification of the posterior longitudinal ligament versus other types of degenerative cervical myelopathy: anterior versus posterior approaches

Background

The debate between anterior or posterior approach for pathologies such as cervical spondylotic myelopathy (CSM) and ossification of the posterior longitudinal ligament (OPLL) have drawn heated debate but are still inconclusive.

Main body of the abstract

A narrative review was performed specifically to study the differences pertaining to OPLL and other causes of degenerative cervical myelopathy (DCM). Current evidence suggests that anterior approach is preferred for K-line (−) OPLL, K-line (+) with canal occupying ratio > 60% and DCM with pre-existing cervical kyphosis. Posterior approach is preferred for K-line (+) OPLL with canal-occupying ratio < 50–60%, and multi-level CSM. No particular advantage for either approach was observed for DCM in a lordotic cervical spine. Anterior approach is generally associated with more complications and thus needs to be weighed carefully during decision-making. The evidence is not convincing for comparing single versus multi-level involvement, and the role of patients' co-morbidity status, pre-existing osteoporosis and co-existent spinal pathologies in influencing patient outcome and surgical options. This should be a platform for future research directives.

Conclusion

From this review, evidence is still inconclusive but there are some factors to consider, and DCM and OPLL should be considered separately for decision-making. Anterior approach is considered for pre-existing cervical kyphosis in DCM, for K-line (−) regardless of canal-occupying ratio, and K-line (+) and canal-occupying ratio > 60% for OPLL patients. Posterior approach is considered for patients with multi-level pathology for DCM, and K-line (+) and canal-occupying ratio < 50–60% for OPLL.

Comparison of 30-Day Outcomes in Patients with Cervical Spine Metastasis Undergoing Corpectomy Versus Posterior Cervical Laminectomy and Fusion: A 2006-2016 ACS-NSQIP Database Study

BACKGROUND

Patients with metastatic disease to the cervical spine have historically had poor outcomes, with an average survival of 15 months. Every effort should be made to avoid complications of surgical intervention for stabilization and decompression.

METHODS

We identified patients who had undergone anterior cervical corpectomy and fusion (ACCF) or posterior cervical laminectomy and fusion (PCLF) for metastatic disease of the cervical spine using the American College of Surgeons National Surgical Quality Improvement Program database from 2006 to 2016. Patients meeting the inclusion criteria were subsequently propensity matched 1:1. We compared the overall complications, intensive care unit level complications, mortality, and return to the operating room between the 2 groups.

RESULTS

After identifying the patients who met the inclusion criteria and propensity matching, a cohort of 240 patients was included, with 120 (50%) in the ACCF group and 120 (50%) in the PCLF group. The patients in the ACCF group were more likely to have experienced any complication (odds ratio, 2.1; 95% confidence interval, 1.1-4.1; P = 0.026) but not severe complications or a return to the operating room (P = 0.406 and P = 0.450, respectively).

CONCLUSION

In the present study, we found that anterior surgical approaches (ACCF) for metastatic cervical spine disease resulted in a significantly greater rate of overall complications (2.1 times more) compared with PCLF in the first 30 days. Although more studies are required to further elucidate this relationship, the general belief that the anterior approach is better tolerated by patients might not apply to patients with metastatic tumors.

Validity of the Japanese core outcome measures index (COMI)-neck for cervical spine surgery: a prospective cohort study

PURPOSE

To investigate the psychometric properties of the Japanese version of the Core Outcome Measures Index-Neck (COMI-Neck) in patients undergoing cervical spine surgery.

METHODS

A total of 177 patients undergoing cervical spine surgery for spinal disorders from April to December 2017 were enrolled. Patient-reported outcomes (PROs) included EuroQOL, Neck Disability Index, and treatment satisfaction. To address whether the questionnaire's scores relate to other outcomes based on a predefined hypothesis, the correlations between the COMI-Neck and the other PROs were measured (Spearman's rank correlation coefficients). The minimum clinically important difference (MCID) of the COMI summary score was calculated using the receiver operating characteristic (ROC) curve with a 7-point Likert scale of satisfaction with the treatment results. To assess reproducibility, another group of 59 volunteers with chronic neck pain were asked to reply to the COMI-Neck twice with an interval of 7-14 days.

RESULTS

The COMI summary score showed no floor or ceiling effects preoperatively or postoperatively. Each of the COMI domains and the COMI summary score correlated to the hypothesized extent with the scores of the reference questionnaires (ρ = 0.40-0.79). According to the ROC curve with satisfaction (including "very satisfied" and "satisfied"), the area under the curve and MCID of the COMI summary score were 0.78 and 2.1. The intraclass correlation coefficient and the minimum detectable change (MDC 95%) of the COMI summary score were 0.97 and 0.77.

CONCLUSION

The Japanese version of the COMI-Neck is valid and reliable for Japanese-speaking patients with cervical spinal disorders.

Increased Rates of Septic Shock, Cardiac Arrest, and Mortality Associated With Chronic Steroid Use Following Anterior Cervical Discectomy and Fusion for Cervical Stenosis

OBJECTIVE

Anterior cervical discectomy and fusion (ACDF) is an established treatment modality for cervical spondylosis. Many patients are on immunosuppressant therapy in the management of various inflammatory spinal pathologies and other comorbid conditions. The impact of chronic steroid use on postoperative complications has not been examined in cervical fusion procedures. The objective of this study was to identify specific postoperative complications associated with steroid/immunosuppressant use following ACDF for cervical stenosis.

METHODS

A multi-institutional surgical registry was queried to identify 5377 patients with ACDF diagnosed with cervical stenosis. Patients were stratified into cohorts with a history of steroid/immunosuppressant use for chronic conditions (n = 198, 3.3%) versus those who did not (n = 5179, 96.7%). Propensity-score matching without replacement was implemented to control for preoperative demographics and comorbidities. Pearson χ² and Fischer exact tests were used in comparing the prevalence of demographics, comorbidities, and complication rates.

RESULTS

Upon propensity matching, increased rates of pulmonary embolisms (0.51% vs 0.00%, P = .025), cardiac arrest requiring resuscitation (1.01% vs 0.10%, P = .020), septic shock (0.51% vs 0.00%, P = .025), and mortality (1.52% vs 0.20%, P = .009) in the postoperative 30-day period in patients on chronic steroid/immunosuppressant use were observed.

CONCLUSIONS

The results indicate that steroid use/immunosuppression in patients with ACDF has a higher associated rate of pulmonary embolisms, cardiac arrest, septic shock, and mortality. The risk of mortality and these other complications should be carefully considered prior to operative intervention. Future research may investigate steroid-tapering protocols that reduce the rate of infection and other postoperative complications in the subset of immunosuppressed ACDF patients.

CLINICAL RELEVANCE

By elucidating the complication rates of ACDF patients on steroids for cervical stenosis, orthopedic surgeons can better stratify patients for risk of postoperative morbidity. Surgeons may have deeper risk-benefit discussions with these specific patients before they elect to have the operation.

Comparison of Perioperative Complications in Anterior Decompression With Fusion and Posterior Decompression With Fusion for Cervical Ossification of the Posterior Longitudinal Ligament: Propensity Score Matching Analysis Using a Nation-Wide Inpatient Database

STUDY DESIGN

A retrospective comparative study.

OBJECTIVE

To compare the perioperative complications and costs of anterior decompression with fusion (ADF) and posterior decompression with fusion (PDF) for patients with cervical ossification of the posterior longitudinal ligament (OPLL).

SUMMARY OF BACKGROUND DATA

Surgical treatment of cervical OPLL has a high risk of various complications. ADF and PDF are effective for the treatment of cervical OPLL; however, few studies have compared the two procedures in terms of the perioperative surgical complications.

METHODS

Patients undergoing ADF and PDF for cervical OPLL from 2010 to 2016 were identified in a nation-wide inpatient database. We investigated systemic and local complications, length of hospital stay, costs for hospitalization, reoperation, and mortality. Propensity score was calculated from patients' characteristics and preoperative comorbidities, and one to one matching was performed.

RESULTS

Propensity score-matching produced 854 pairs of patients who underwent ADF and PDF. The rate of at least one systemic complication was significantly higher in the ADF group (P = 0.004). The incidence rates of postoperative respiratory failure (P = 0.034) and dysphagia (P = 0.008) were significantly higher in the ADF group. The rates of pneumonia (P = 0.06) and hoarseness (P = 0.08) also tended to be higher in the ADF group. However, no difference was found in the mortality rate (P = 0.22). In the local complications, spinal fluid leakage was significantly higher in the ADF group (P < 0.001). However, blood transfusion rate was significantly higher in the PDF group (P = 0.001). Hospital stay was significantly longer in the PDF group (P < 0.001) and the cost for hospitalization was greater in the PDF group (P < 0.001).

CONCLUSION

The present study demonstrated that perioperative complications, such as respiratory failure, dysphagia, and spinal fluid leakage, were more common in the ADF group. However, hospital stay was longer in the PDF group, and the cost for hospitalization was greater in the PDF group.

LEVEL OF EVIDENCE

3.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Outcomes following outpatient anterior cervical discectomy and fusion for the treatment of myelopathy

INTRODUCTION

Anterior cervical discectomy and fusion (ACDF) is a commonly performed procedure for the treatment of degenerative cervical disease. With continued increase in U.S. healthcare expenditure, surgeons have begun to more closely examine the benefits of performing ACDF in an outpatient setting to increase efficiency, reduce the overall financial burden on patients/providers, and provide streamlined care for these patients. The purpose of this study was to analyze outcomes following outpatient ACDF for the treatment of myelopathy.

METHODS

14,490 patients who had undergone ACDF for myelopathy from 2010 to 2018 were included in this retrospective study, of which 2956 (20.40%) patients were considered to have undergone outpatient surgery. Pearson chi-squared tests and Fischer's Exact Tests were used to analyze differences in categorical variables of demographics, preoperative comorbidities, and postoperative complications, while Mann-Whitney-U-Tests were used to compare mean values of continuous variables. Coarsened-exact-matching (CEM) was implemented to control for baseline differences in demographics and comorbidities, and post-matching diagnostics included multivariate and univariate imbalance measure assessment. Outcomes were compared between the CEM-matched inpatient and outpatients ACDF cohorts.

RESULTS

Upon CEM-matching (L1-statistic <0.001), the outpatient cohort (n = 2610, 25.13%) demonstrated significantly lower rates of any complication (p < 0.001), minor complications (p = 0.001), urinary tract infections (p = 0.029), blood transfusions (p < 0.001), major complications (p < 0.001), deep incisional surgical site infections (p = 0.017), ventilator dependence (p = 0.027), cardiac arrest (p = 0.028), unplanned reoperations (p = 0.001), and mortality (p = 0.006) in the 30-day postoperative period when compared to inpatient controls (n = 7774, 74.87%).

CONCLUSION

ACDF has been a target amongst spinal procedures as a prime candidate for outpatient surgery. However, no previous reports have described complication rates and perioperative parameters in the sub-population of outpatient ACDF patients with myelopathy. In addition to shorter times from admission to operating room, operative time, and LOS, our study also demonstrated lower rates of major and overall complications in outpatient ACDF's for myelopathy in comparison to their inpatient counterparts. Performing ACDF's for myelopathy in an outpatient setting may help to curb costs, improve outcomes, and serve as a valuable learning resource for graduate medical education with rapid turnovers and shorter operative times.

Defining threshold values on the neck disability index corresponding to a patient acceptable symptom state in patients undergoing elective surgery for degenerative disorders of the cervical spine

BACKGROUND CONTEXT

The patient acceptable symptom state (PASS) has emerged as a novel tool for interpreting patient-reported outcomes. While the minimal clinically important difference values for various spine outcome instruments have been defined, little is known about the PASS thresholds for these measures.

PURPOSE

To define threshold values on the neck disability index (NDI) corresponding to a PASS in patients undergoing surgery for degenerative disorders of the cervical spine.

STUDY DESIGN

Retrospective review of prospectively collected registry data.

PATIENT SAMPLE

The sample includes 613 patients who underwent anterior cervical discectomy and fusion for degenerative spine conditions between 2005 and 2014.

OUTCOME MEASURES

The main outcome measure was the NDI. The PASS anchor question was adapted from the NASS questionnaire, "How would you rate the overall results of your treatment?" and the validation question was adapted from the AAOS cervical spine questionnaire, "Would you have the same treatment again if you had the same condition?"

METHODS

Patients were assessed preoperatively, 6 months and 2 years postoperatively using the NDI. Responses to the anchor question were dichotomized and used as the external criterion in receiver operating characteristics analysis to define thresholds on the NDI that corresponded to a PASS at 2 years postoperatively. Sensitivity analyses were carried out for various subgroups (age, gender, BMI, comorbidity status), baseline NDI (tertiles), time of follow-up (6 months and 2 years) and an alternate definition of PASS.

RESULTS

Of the 613 patients, 503 (82%) completed 2-year follow-up, of which, 81% reported their current state as acceptable. The areas under the curve (AUC) for the receiver operating characteristics were 0.75 to 0.89 for all analyses, indicating a good ability of the NDI to discriminate between attaining a satisfactory state or not. The PASS threshold was ≤15 points at 6 months (AUC 0.81, sensitivity 73%, specificity 79%) and ≤17 points at 2 years (AUC 0.80, sensitivity 86%, specificity 65%). Sensitivity analyses revealed that the 17-point threshold on the NDI was robust. PASS responders were approximately 12 times more likely to be satisfied (adjusted odds ratio 12.11, 95% confidence intervals 6.96-21.07) and 6 times more willing to undergo surgery again (adjusted odds ratio 6.12, 95% confidence intervals 3.47-10.80) compared to nonresponders.

CONCLUSIONS

Patients with a NDI of ≤17 consider their postoperative symptom state to be acceptable. This PASS threshold can be used alongside the minimal clinically important difference when defining treatment success in spine outcomes studies. At the individual level, this threshold provides clinically relevant benchmarks for surgeons when assessing a patient's postoperative recovery.

Clinical predictors of achieving the minimal clinically important difference after surgery for cervical spondylotic myelopathy: an external validation study from the Canadian Spine Outcomes and Research Network

OBJECTIVE

Recently identified prognostic variables among patients undergoing surgery for cervical spondylotic myelopathy (CSM) are limited to two large international data sets. To optimally inform shared clinical decision-making, the authors evaluated which preoperative clinical factors are significantly associated with improvement on the modified Japanese Orthopaedic Association (mJOA) scale by at least the minimum clinically important difference (MCID) 12 months after surgery, among patients from the Canadian Spine Outcomes and Research Network (CSORN).

METHODS

The authors performed an observational cohort study with data that were prospectively collected from CSM patients at 7 centers between 2015 and 2017. Candidate variables were tested using univariable and multiple binomial logistic regression, and multiple sensitivity analyses were performed to test assumptions about the nature of the statistical models. Validated mJOA MCIDs were implemented that varied according to baseline CSM severity.

RESULTS

Among 205 patients with CSM, there were 64 (31%) classified as mild, 86 (42%) as moderate, and 55 (27%) as severe. Overall, 52% of patients achieved MCID and the mean change in mJOA score at 12 months after surgery was 1.7 ± 2.6 points (p < 0.01), but the subgroup of patients with mild CSM did not significantly improve (mean change 0.1 ± 1.9 points, p = 0.8). Univariate analyses failed to identify significant associations between achieving MCID and sex, BMI, living status, education, smoking, disability claims, or number of comorbidities. After adjustment for potential confounders, the odds of achieving MCID were significantly reduced with older age (OR 0.7 per decade, 95% CI 0.5-0.9, p < 0.01) and higher baseline mJOA score (OR 0.8 per point, 95% CI 0.7-0.9, p < 0.01). The effects of symptom duration (OR 1.0 per additional month, 95% CI 0.9-1.0, p = 0.2) and smoking (OR 0.4, 95% CI 0.2-1.0, p = 0.06) were not statistically significant.

CONCLUSIONS

Surgery is effective at halting the progression of functional decline with CSM, and approximately half of all patients achieve the MCID. Data from the CSORN confirmed that older age is independently associated with poorer outcomes, but novel findings include that patients with milder CSM did not experience meaningful improvement, and that symptom duration and smoking were not important. These findings support a nuanced approach to shared decision-making that acknowledges some prognostic uncertainty when weighing the various risks, benefits, and alternatives to surgical treatment.

Identifying the Characteristics of Patients With Cervical Degenerative Disease for Surgical Treatment From 17-Year Real-World Data: Retrospective Study

Background

Real-world data (RWD) play important roles in evaluating treatment effectiveness in clinical research. In recent decades, with the development of more accurate diagnoses and better treatment options, inpatient surgery for cervical degenerative disease (CDD) has become increasingly more common, yet little is known about the variations in patient demographic characteristics associated with surgical treatment.

Objective

This study aimed to identify the characteristics of surgical patients with CDD using RWD collected from electronic medical records.

Methods

This study included 20,288 inpatient surgeries registered from January 1, 2000, to December 31, 2016, among patients aged 18 years or older, and demographic data (eg, age, sex, admission time, surgery type, treatment, discharge diagnosis, and discharge time) were collected at baseline. Regression modeling and time series analysis were conducted to analyze the trend in each variable (total number of inpatient surgeries, mean age at surgery, sex, and average length of stay). A P value <.01 was considered statistically significant. The RWD in this study were collected from the Orthopedic Department at Peking University Third Hospital, and the study was approved by the institutional review board.

Results

Over the last 17 years, the number of inpatient surgeries increased annually by an average of 11.13%, with some fluctuations. In total, 76.4% (15,496/20,288) of the surgeries were performed in patients with CDD aged 41 to 65 years, and there was no significant change in the mean age at surgery. More male patients were observed, and the proportions of male and female patients who underwent surgery were 64.7% (13,126/20,288) and 35.3% (7162/20,288), respectively. However, interestingly, the proportion of surgeries performed among female patients showed an increasing trend (P<.001), leading to a narrowing sex gap. The average length of stay for surgical treatment decreased from 21 days to 6 days and showed a steady decline from 2012 onward.

Conclusions

The RWD showed its capability in supporting clinical research. The mean age at surgery for CDD was consistent in the real-world population, the proportion of female patients increased, and the average length of stay decreased over time. These results may be valuable to guide resource allocation for the early prevention and diagnosis, as well as surgical treatment of CDD.

Degenerative Cervical Myelopathy: A Brief Review of Past Perspectives, Present Developments, and Future Directions

Degenerative cervical myelopathy (DCM) is the most common cause of spinal cord injury in developed countries; its prevalence is increasing due to the ageing of the population. DCM causes neurological dysfunction and is a significant cause of disability in the elderly. It has important negative impacts on the quality of life of those affected, as well as on their caregivers. DCM is triggered by a variety of degenerative changes in the neck, which affect one or more anatomical structures, including intervertebral discs, vertebrae, and spinal canal ligaments. These changes can also lead to structural abnormalities, leading to alterations in alignment, mobility, and stability. The principle unifying problem in this disease, regardless of the types of changes present, is injury to the spinal cord due to compression by static and/or dynamic forces. This review is partitioned into three segments that focus on key elements of the past, the present, and the future in the field, which serve to introduce the focus issue on "Degenerative Cervical Myelopathy and the Aging Spine". Emerging from this review is that tremendous progress has been made in the field, particularly in recent years, and that there are exciting possibilities for further advancements of patient care.

Is Modified K-line a Powerful Tool of Surgical Decision Making for Patients With Cervical Spondylotic Myelopathy?

STUDY DESIGN

Prospective observational single-center study.

OBJECTIVE

To evaluate anterior decompression and fusion (ADF) or posterior surgery (PS) for patients with cervical spondylotic myelopathy (CSM) using the modified K-line (mK-line) and to compare clinical and radiologic outcomes between these 2 techniques.

SUMMARY OF BACKGROUND DATA

The authors have previously reported that insufficient posterior decompression is often seen after laminoplasty for CSM in patients with preoperative anterior clearance of the spinal cord <4 mm on the basis of the mK-line. However, to our knowledge, no study has investigated the role, if any, of the mK-line in surgical decision making for patients with CSM.

METHODS

A total of 87 patients were enrolled who underwent surgery for treatment of CSM between 2011 and 2015 at our hospital and who could be followed up for at least 2 years. ADF was selected as a more favorable procedure than PS in patients with anterior spinal clearance of <4 mm on preoperative midsagittal magnetic resonance imaging. On the basis of the Japanese Orthopedic Association (JOA) scoring system for cervical myelopathy, the rate of recovery of the JOA scores at 2 years after surgery was investigated as a clinical outcome to compare these 2 groups.

RESULTS

Mean age was 65.1 (±12.9) years in the ADF group (n=26) and 70.5 (±8.6) years in the PS group (n=61). In the PS group, 10 patients underwent posterior decompression with fusion. Mean preoperative and postoperative JOA scores were 10.5 and 14.1 points in the ADF group and 9.8 and 13.1 points in the PS group, respectively, showing no significant difference in recovery rate of JOA score between the ADF (58.9%) and PS (47.1%) groups. However, patients with a minimum interval between the mK-line and the anterior compression factor on the midsagittal image (minimum interval of the spinal cord) <4 mm tended to have unsatisfactory outcomes (recovery rate 29.6%) compared with patients with minimum interval of the spinal cord >4 mm (53.6%, P=0.07) in the PS group.

CONCLUSION

Preoperative intervention using the mK-line is useful to predict residual cord compression and might homogenize postoperative clinical outcomes in both anterior surgery and PS.

Degenerative Cervical Myelopathy; A Review of the Latest Advances and Future Directions in Management

The assessment, diagnosis, operative and nonoperative management of degenerative cervical myelopathy (DCM) have evolved rapidly over the last 20 years. A clearer understanding of the pathobiology of DCM has led to attempts to develop objective measurements of the severity of myelopathy, including technology such as multiparametric magnetic resonance imaging, biomarkers, and ancillary clinical testing. New pharmacological treatments have the potential to alter the course of surgical outcomes, and greater innovation in surgical techniques have made surgery safer, more effective and less invasive. Future developments for the treatment of DCM will seek to improve the diagnostic accuracy of imaging, improve the objectivity of clinical assessment, and increase the use of surgical technology to ensure the best outcome is achieved for each individual patient.