Neurologic recovery after anterior cervical discectomy and fusion

Perioperative inpatient falls for anterior cervical discectomy and fusion patients are on the rise: risk factors associated with this "never event"

BACKGROUND CONTEXT

Patients undergoing anterior cervical discectomy and fusion (ACDF) often have brief inpatient stays and may be at risk for inpatient falls (IPFs). Such IPFs should be preventable and have been termed a "never event" by the National Quality Forum, an affiliate of The Joint Commission. Despite increasing attention to IPF prevention, no studies have investigated the incidence, trends, and factors associated with IPFs among ACDF patients.

PURPOSE

To characterize the trends in the incidence of ACDF-related IPFs and their risk factors.

STUDY DESIGN/SETTING

Retrospective cohort study.

PATIENT SAMPLE

Adult patients who underwent inpatient ACDF between 2010 and Q3 2022 were abstracted from a large, national, multiinsurance administrative claims database.

OUTCOME MEASURES

Incidence, trends, and factors associated with IPFs.

METHODS

Adult patients who had undergone single or multilevel inpatient ACDF were identified by administrative coding. Exclusion criteria included: patients <18 years of age, those who underwent outpatient ACDF, concurrent posterior cervical procedures, thoracic or lumbar fusion, and those with trauma, neoplasm, or infection diagnosed within 90-days prior to surgery. The subset of patients who suffered an IPF were subsequently identified. The annual incidence of IPFs was analyzed over the study years and various risk factors were assessed for their correlation with IPFs by multivariable logistic regression. To determine the association between IPF and length of stay (LOS), patients with relative to without IPF were matched 1:4 based on age, sex, and Elixhauser Comorbidity Index (ECI) and compared by multivariable logistic regression.

RESULTS

Of the 294,165 inpatient ACDF patients meeting inclusion criteria, IPFs were identified for 5,548 (1.9%). Between 2010 and Q3 2022, the annual incidence of IPFs increased from 309 (1.1%) to 515 (4.8%) for patients undergoing ACDF (p<.001). Independent predictors of an IPF were: hospital-acquired delirium (odds ratio [OR] 4.50), history of prior falls (OR 3.38), hospital-acquired psychosis (OR 3.17), alcohol use disorder (OR 2.68), cervical myelopathy (relative to radiculopathy) (OR 2.66), socioeconomically disadvantaged patients (OR 1.85), history of dementia (OR 1.77), underweight body mass index (BMI <18.5) (OR 1.67), multilevel ACDF (OR 1.43), history of prior cervical surgery (OR 1.41), male sex (OR 1.37), Medicaid insurance (OR 1.34), older age (OR 1.33), patients in the northeast United States (OR 1.15), and obese BMI >30 (OR 1.15) (p<.001 for all). Relative to patients without IPF, patients who suffered an IPF following ACDF demonstrated incrementally increasing odds of extended LOS (4-5 days [OR 2.63], 6 to 7 days [OR 3.85], 7+ days [OR 6.78]) (p<.001 for all).

CONCLUSION

In this robust national sample of patients undergoing inpatient ACDF, IPFs were identified for 1.9%, with an increasing annual incidence over the years. Among these patients, various factors were associated with their occurrence, many of which may be potentially modifiable. These findings have major clinical implications on care pathway optimization regarding early identification of high-risk patients undergoing ACDF and lays a foundation for the refinement of multidisciplinary fall prevention programs.

Effect of Preoperative Motor Weakness on Postoperative Clinical Outcomes in Patients Undergoing Cervical Disk Replacement

STUDY DESIGN

This is a retrospective review.

OBJECTIVE

To examine the effect of preoperative motor weakness on clinical outcomes in patients undergoing cervical disk replacement (CDR).

SUMMARY OF BACKGROUND DATA

Studies examining the effect of preoperative motor weakness on postoperative clinical outcomes in CDR are limited.

METHODS

Patient cohorts were based on documented upper-extremity motor weakness on physical exam versus no motor weakness. Demographics, perioperative characteristics, and preoperative patient-reported outcome measures (PROMs) were compared using univariate inferential statistics. PROMs consisted of Visual Analog Pain Scale-Neck (VAS-N), Patient-Reported Outcomes Measurement Information System Physical Function (PROMIS-PF), VAS-Arm (VAS-A), 12-Item Short Form (SF-12) Physical Component Score (PCS), Oswestry Neck Disability Index (NDI), and SF-12 Mental Component Score (MCS). Postoperative PROMs were collected at the 6-week, 12-week, 6-month, and final follow-up up to 1-yeartime points, and intercohort minimum clinically important difference (MCID) achievement was compared through multivariable linear logistic regression adjusting for significant differences in preoperative characteristics.

RESULTS

A total of 118 patients formed cohorts based on documented upper-extremity weakness (n=73) versus no weakness (n=45). The average time to postoperative follow-up was 9.7±7.0 mo. The differences in insurance type between the 2 cohorts were significant ( P <0.042). Perioperative diagnosis of foraminal stenosis was significantly more common in the motor weakness cohort ( P <0.013). There were no differences in reported PROMs between cohorts. Patients with motor weakness reported significant MCID achievement for PROMIS-PF at 6-/12-weeks ( P <0.012, P <0.041 respectively), SF-12 PCS at 6-months ( P <0.042), VAS-N at final follow-up ( P <0.021), and NDI at final follow-up ( P <0.013).

CONCLUSIONS

CDR patients with preoperative muscle weakness achieved MCID across several PROMs compared with patients without muscle weakness. Patients with motor weakness reported greater improvement in mental health, pain, and disability as early as 6 weeks and up to 1 year after CDR. This information serves to inform physicians that motor weakness may not indicate a negative overall outcome.

Implant Design and Cervical Spinal Biomechanics and Neurorehabilitation: A Finite Element Investigation

INTRODUCTION

The cervical spine, pivotal for mobility and overall body function, can be affected by cervical spondylosis, a major contributor to neural disorders. Prevalent in both general and military populations, especially among pilots, cervical spondylosis induces pain and limits spinal capabilities. Anterior Cervical Discectomy and Fusion (ACDF) surgery, proposed by Cloward in the 1950s, is a promising solution for restoring natural cervical curvature. The study objective was to investigate the impacts of ACDF implant design on postsurgical cervical biomechanics and neurorehabilitation outcomes by utilizing a biofield head-neck finite element (FE) platform that can facilitate scenario-specific perturbations of neck muscle activations. This study addresses the critical need to enhance computational models, specifically FE modeling, for ACDF implant design.

MATERIALS AND METHODS

We utilized a validated head-neck FE model to investigate spine-implant biomechanical interactions. An S-shaped dynamic cage incorporating titanium (Ti) and polyetheretherketone (PEEK) materials was modeled at the C4/C5 level. The loading conditions were carefully designed to mimic helmet-to-helmet impact in American football, providing a realistic and challenging scenario. The analysis included intervertebral joint motion, disk pressure, and implant von Mises stress.

RESULTS

The PEEK implant demonstrated an increased motion in flexion and lateral bending at the contiguous spinal (C4/C5) level. In flexion, the Ti implant showed a modest 5% difference under 0% activation conditions, while PEEK exhibited a more substantial 14% difference. In bending, PEEK showed a 24% difference under 0% activation conditions, contrasting with Ti's 17%. The inclusion of the head resulted in an average increase of 18% in neck angle and 14% in C4/C5 angle. Disk pressure was influenced by implant material, muscle activation level, and the presence of the head. Polyetheretherketone exhibited lower stress values at all intervertebral disc levels, with a significant effect at the C6/C7 levels. Muscle activation level significantly influenced disk stress at all levels, with higher activation yielding higher stress. Titanium implant consistently showed higher disk stress values than PEEK, with an orders-of-magnitude difference in von Mises stress. Excluding the head significantly affected disk and implant stress, emphasizing its importance in accurate implant performance simulation.

CONCLUSIONS

This study emphasized the use of a biofidelic head-neck model to assess ACDF implant designs. Our results indicated that including neck muscles and head structures improves biomechanical outcome measures. Furthermore, unlike Ti implants, our findings showed that PEEK implants maintain neck motion at the affected level and reduce disk stresses. Practitioners can use this information to enhance postsurgery outcomes and reduce the likelihood of secondary surgeries. Therefore, this study makes an important contribution to computational biomechanics and implant design domains by advancing computational modeling and theoretical knowledge on ACDF-spine interaction dynamics.

Long-Term (>24 Months) Duration of Symptoms Negatively Impacts Patient-Reported Outcomes Following Anterior Cervical Discectomy and Fusion for Cervical Radiculopathy

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To investigate the impact of long symptom duration (>24 mo) on patient self-reported outcomes for pain, function, and quality of life following anterior cervical discectomy and fusion (ACDF) for cervical radiculopathy.

SUMMARY OF BACKGROUND DATA

ACDF is an effective treatment to relieve the symptoms of cervical radiculopathy. However, there is no consensus on whether prolonged preoperative length of symptoms negatively impacts postoperative outcomes.

METHODS

This study included consecutive patients who underwent ACDF for cervical radiculopathy from May 1, 2012 to Dec 1, 2019 by a single surgeon. Patients were stratified by short (<24 mo) and long (>24 mo) duration of symptoms. Outcomes including visual analog scale (VAS) neck and arm, neck disability index (NDI), EuroQol-5D (EQ-5D), and overall state of health (EQ-VAS) were compared between cohort both for absolute values and percentage of patients achieving minimal clinically important difference.

RESULTS

A total of 111 consecutive patients were included in our study, including 59 patients in the short symptom duration group and 52 patients in the long symptom duration group. The mean age of the patients was 51.4±9.4 and 41 (36.9%) were female. The baseline VAS neck and arm, NDI, EQ-5D, and EQ-VAS were similar between groups. Patients in both long and short symptom duration groups had clinical improvement following surgery. However, patients with short symptom duration had better VAS Neck and EQ-5D outcomes, and were more likely to meet minimal clinically important difference for NDI, EQ-5D, or any outcome. Multivariate analysis confirmed symptom duration <24 months as an independent predictor for better patient-reported outcomes.

CONCLUSION

We appreciated better clinical outcomes in patients with shorter symptom duration who received ACDF for cervical radiculopathy. On the basis of this data, we advocate for prompt treatment of cervical radiculopathy to avoid the potential for long-term impairment.

LEVEL OF EVIDENCE

Level 3.

Complications of Cervical Endoscopic Spinal Surgery: A Systematic Review and Narrative Analysis

BACKGROUND

There are no systematic evidence-based medical data on the complications of endoscopic cervical spinal surgery. This narrative analysis compiled data from various studies that examined endoscopic complications, such as cervical disc herniation and foraminal stenosis. This study aimed to investigate the efficacy and safety of endoscopic surgery in cervical radiculopathy.

METHODS

We searched the PubMed/MEDLINE databases to identify articles on endoscopic spinal surgery, and keywords were set as "endoscopic cervical spinal surgery", "endoscopic cervical discectomy", "endoscopic cervical foraminotomy", and "percutaneous endoscopic cervical discectomy". We analyzed the evidence level and classified the prescribed complications according to the literature. Endoscopic cervical surgery was divided into three categories: full endoscopic anterior, endoscopic posterior, and unilateral biportal approaches. We excluded duplicate publications, studies without full text, studies without complications or incomplete information, and studies that did not provide the necessary data for extraction, animal experiments, or reviews.

RESULTS

Difficulties in swallowing, hematoma, and hoarseness are common complications associated with the anterior cervical approach. In contrast, complications of the posterior approach include nerve root injury, hematoma, and dysesthesia. However, endoscopic cervical spinal surgery, including the full endoscopic anterior, posterior, and unilateral biportal approaches, is a safe and effective treatment for cervical radiculopathy.

CONCLUSIONS

Complications of full endoscopic cervical spinal surgery differ significantly depending on the anterior and posterior approaches. In the anterior approach, swallowing difficulty, recurrent disc, hematoma, and dysphonia are the common complications. In contrast, transient dysesthesia, dural tears, upper limb motor deficits, and persistent arm pain are commonly reported with the posterior approach.

Differences in Time to Achieve Minimum Clinically Important Difference Between Patients Undergoing Anterior Cervical Discectomy and Fusion and Cervical Disc Replacement

OBJECTIVE

To compare patients undergoing anterior cervical discectomy and fusion (ACDF) versus cervical disc replacement (CDR) for time to minimum clinically important difference (MCID) achievement and predictors of delayed MCID achievement for the patient-reported outcomes (PROs), Patient-Reported Outcomes Measurement Information System Physical Function, Neck Disability Index, Visual Analog Scale (VAS) neck, and VAS arm.

METHODS

PROs of patients undergoing ACDF or CDR were collected preoperatively and postoperatively at 6-week/12-week/6-month/1-year/2-year periods. MCID achievement was calculated through comparison of changes in Patient-Reported Outcomes Measurement to previously established values in literature. Time to MCID achievement and predictors for delayed MCID achievement were determined through Kaplan-Meier survival analysis and multivariable Cox regression, respectively.

RESULTS

One hundred ninety-seven patients were identified, with 118 and 79 undergoing ACDF and CDR, respectively. Kaplan-Meier survival analysis demonstrated faster time to achieve MCID for CDR patients in Patient-Reported Outcomes Measurement Information System Physical Function (P = 0.006). Early predictors of MCID achievement through Cox regression were CDR procedure, Asian ethnicity, elevated preoperative PROs of VAS neck and VAS arm (hazard ratio, 1.16-7.28). Workers' compensation was a late predictor of MCID achievement (hazard ratio, 0.15).

CONCLUSIONS

Most patients achieved MCID in physical function, disability, and back pain outcomes within 2 years of surgery. Patients undergoing CDR achieved MCID faster in physical function. Early predictors of MCID achievement were CDR procedure, Asian ethnicity, and elevated preoperative PROs of pain outcomes. Workers' compensation was a late predictor. These findings may be helpful in managing patient expectations.

Does Symptom Duration Prior to Anterior Cervical Discectomy and Fusion for Disc Herniation Influence Patient-Reported Outcomes in a Workers' Compensation Population?

OBJECTIVE

To evaluate the influence of symptom duration before anterior cervical discectomy and fusion (ACDF) on patient-reported outcomes (PROs) in workers' compensation patients.

METHODS

A prospective registry was searched for workers' compensation patients who underwent ACDF for herniated disc. Two cohorts based on symptom duration were formed: lesser duration (LD) (<6 months) and prolonged duration (PD) (≥6 months). PROs were collected preoperatively and at 6 weeks, 12 weeks, 6 months, and 1 year postoperatively. PROs were compared within and between groups. Rates of minimum clinically important difference (MCID) were compared between groups.

RESULTS

The study included 63 patients. The LD cohort reported improvement in Patient-Reported Outcomes Measurement Information System-Physical Function (PROMIS-PF), Neck Disability Index (NDI), and visual analog scale (VAS) neck at 12 weeks and 6 months and VAS arm at all periods (all P ≤ 0.036). The LD cohort reported improvement in NDI at 12 weeks and 6 months and VAS arm at 6 weeks, 12 weeks, and 6 months (all P ≤ 0.037). Between groups, the LD cohort demonstrated superior scores in PROMIS-PF at 6 weeks, 12 weeks, and 6 months; NDI preoperatively and at 6 weeks, 12 weeks, and 6 months; VAS neck at 12 weeks; and 9-item Patient Health Questionnaire (PHQ-9) at 6 months (all P ≤ 0.045). The LD group was more likely to achieve MCID in PROMIS-PF at 12 weeks (P = 0.012). The PD group was more likely to achieve MCID in PHQ-9 at 6 months (P = 0.023).

CONCLUSIONS

Regardless of length of symptom duration before ACDF in workers' compensation patients, the patients demonstrated improvements in disability and arm pain. Patients with LD also demonstrated improvements in physical function and neck pain. Patients with LD demonstrated superior scores in physical function, pain, disability, and mental health and were more likely to achieve clinically significant improvement in physical function. Patients with PD were more likely to achieve clinically significant improvement in mental health.

Appraising The Evidence for Conservative versus Surgical Management of Motor Deficits in Degenerative Cervical Radiculopathy

STUDY DESIGN

Systematic review.

OBJECTIVES

Understanding the prevalence and outcome of motor deficits in degenerative cervical radiculopathy is important to guide management. We compared motor radiculopathy outcomes after conservative and surgical management, a particular focus being painful vs painless radiculopathy.

METHODS

MEDLINE and EMBASE databases were searched. We stratified each study cohort into 1 of 6 groups, I-VI, based on whether radiculopathy was painful, painless or unspecified, and whether interventions were surgical or non-surgical.

RESULTS

Of 10 514 initial studies, 44 matched the selection criteria. Whilst 42 (95.5%) provided baseline motor radiculopathy data, only 22 (50.0%) provided follow-up motor outcomes. Mean baseline prevalence of motor deficits was 39.1% (9.2%-73.3%) in conservative cohorts and 60.5% (18.5%-94.1%) in surgical cohorts. Group VI, 'surgically-managed motor radiculopathy with unclear pain status' had the largest number of cohorts. Conversely, no cohorts were found in Group III, 'conservatively-managed painless motor radiculopathy'. Large disparities in data quality made direct comparison of conservative vs operative management difficult.

CONCLUSIONS

Overall pre-intervention prevalence of motor deficits in degenerative cervical radiculopathy is 56.4%. Many studies fail to report motor outcomes after intervention, meaning statistical evidence to guide optimal management of motor radiculopathy is currently lacking. Our study highlights the need for more evidence, preferably from a prospective long-term study, to allow direct comparisons of motor outcomes after conservative and surgical management.

Indicators for Substantial Neurological Recovery Following Elective Anterior Cervical Discectomy and Fusion

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The purposes of this study were to determine the rate of improvement of significant preoperative weakness, identify risk factors for failure to improve, and characterize the motor recovery of individual motor groups.

SUMMARY OF BACKGROUND DATA

While neck and arm pain reliably improve following anterior cervical discectomy and fusion (ACDF), the frequency and magnitude of motor recovery following ACDF remain unclear.

METHODS

We performed a retrospective review of patients undergoing 1-4-level ACDF at a single institution between September 2015 and June 2016. Patients were subdivided into 2 groups based upon the presence or absence of significant preoperative weakness, which was defined as a motor grade <4 in any single upper extremity muscle group. Clinical notes were reviewed to determine affected muscle groups, rates of motor recovery, and risk factors for failure to improve.

RESULTS

We identified 618 patients for inclusion. Significant preoperative upper extremity weakness was present in 27 patients (4.4%). Postoperatively, 19 of the affected patients (70.3%) experienced complete strength recovery, and 5 patients (18.5%) experienced an improvement in muscle strength to a motor grade ≥4. The rate of motor recovery postoperatively was 85.7% in the triceps, 83.3% in the finger flexors, 83.3% in the hand intrinsics, 50.0% in the biceps, and 25.0% in the deltoids. Risk factors for failure to experience significant motor improvement were the presence of myelomalacia (odds ratio: 28.9, P <0.01) and the performance of >2 levels of ACDF (odds ratio: 10.1, P <0.01).

CONCLUSIONS

Patients with substantial preoperative upper extremity weakness can expect high rates of motor recovery following ACDF, though patients with deltoid weakness, myelomalacia, and >2 levels of ACDF are less likely to experience significant motor improvement.

Anterior Cervical Discectomy and Fusion: A Surgical Intervention for Treating Cervical Disc Disease

Cervical disc disease includes chronic disc degeneration, stenosis, spondylosis, and disc herniation; providers initially treat these conditions conservatively through symptomatic care. When conservative measures fail, surgery may be indicated. It is important to explore all the surgical options available and the risks and benefits of each procedure. An anterior cervical discectomy and fusion (ACDF) is a procedure involving the removal of disc material to achieve neural tissue decompression and placement of a bone graft or interbody implant and a cervical plate and screws to stabilize the spinal column at one or more vertebral levels. This article briefly reviews the anatomy of the spine and treatment options for cervical disc disease; presents an in-depth review of the ACDF procedure, including the expected perioperative course and care considerations; and concludes with a case report of a 37-year-old woman who underwent an ACDF at the C5-C6 and C6-C7 vertebral levels of the spine.

Young adults undergoing ACDF surgery exhibit decreased health-related quality of life in the long term in comparison to the general population

BACKGROUND CONTEXT

The leading surgical treatment of cervical radiculopathy is anterior cervical discectomy and fusion (ACDF). However, it has been suggested that ACDF procedures could lead to accelerated degeneration of the adjacent cervical discs (adjacent segment disease, or ASD) and the effect of ACDF surgery on neck symptoms and quality of life in the long term is not fully understood. Patients operated on at young ages generally have a long life expectancy and a long number of working years ahead of them. Thus, this patient group is of special interest when considering the accumulation of cervical problems due to possible ASD, the overall progressive nature of cervical degeneration in the long term, and their effects on related quality of life.

PURPOSE

Our goal was to study the health-related quality of life in the long-term follow-up after ACDF surgery in the young adult population between the ages of 18 and 40.

STUDY DESIGN

A retrospective cohort study with propensity matched controls.

PATIENT SAMPLE

All patients between 18 and 40 years of age at the time of the surgery who underwent ACDF due to degenerative cervical disease at Helsinki University Hospital between the years 1990 and 2005 who had filled in the quality of life questionnaires 12 to 28 years after the surgery (281 patients), and a propensity matched control cohort of the general population selected based on age, sex, and smoking status.

OUTCOME MEASURES

Quality of life measured by the EuroQol questionnaire (EQ-5D-3L and EQ-VAS).

METHODS

The medical records of all patients who underwent ACDF due to degenerative cervical disease at the age of 18 to 40 years at Helsinki University Hospital between 1990 and 2005 were analyzed retrospectively. The EuroQol questionnaire was sent to all patients whose contact information could be obtained (443 patients) at the end of the follow-up (median 17.5 years) to assess their current quality of life. A total of 281 patients returned the questionnaires and were included in this study. Quality of life was compared to that in the general Finnish population using a similar sized control cohort selected through propensity matching.

RESULTS

The patients who had undergone ACDF surgery reported significantly more problems than the general population cohort in three out of five dimensions that were assessed in the EQ-5D questionnaire, including mobility, usual activities, and pain/discomfort. Similarly, the overall EQ-5D-3L index calculated from the dimensional values was lower (0.74 vs. 0.83, p=.000), depicting a generally decreased health-related quality of life among patients. Spondylosis as a primary diagnosis, clinical myelopathy, and further cervical surgeries were associated with lower quality of life in the subgroup analyses of the patients. Similarly, in the EQ-VAS assessment, patient subgroups with spondylosis as a primary diagnosis, at least one reoperation, operation on more than one level, and clinical myelopathy were associated with lower scores and lower quality of life. The mean EQ-VAS score among patients was 73%. Regardless of the decreased health-related quality of life, there was no statistically significant difference in the concurrent employment status between the patient and control groups.

CONCLUSIONS

The health-related life quality measured by the EQ-5D-3L was lower in the patient population than in the general population. Patients had more problems with mobility and usual activities and more pain/discomfort. However, satisfaction with the surgery was very high, and there was no significant difference in employment status between the patients and the control population. Patients with spondylosis as a primary diagnosis had lower quality of life compared to patients with disc herniation. Also, clinical myelopathy and further cervical surgeries during follow-up were associated with lower quality of life in the subgroup analyses of the patients. It must also be kept in mind that we do not know what the situation could have been without surgery and with conservative treatment only.

Impact of preoperative weakness and duration of symptoms on health-related quality-of-life outcomes following anterior cervical discectomy and fusion

BACKGROUND CONTEXT

The majority of patients with preoperative upper extremity weakness show improvements in motor function after anterior cervical discectomy and fusion (ACDF). Although numerous studies have examined both the extent and time course to which motor function can be expected to improve, few have shown that these improvements in motor function translate to improved health related quality of life (HRQOL) outcomes.

PURPOSE

The purpose of this study was to examine the effect of preoperative weakness and duration of symptoms on HRQOL outcomes in patients who underwent ACDF.

STUDY DESIGN

Retrospective cohort study.

PATIENT SAMPLE

Adult patients who underwent an ACDF procedure at an academic hospital from January 2015 to December 2016 by a fellowship-trained spine surgeon.

OUTCOME MEASURES

The primary outcomes of interest were HRQOL outcomes: Short Form-12 Physical/Mental Component Scores (SF-12 PCS/MCS), Neck Disability Index (NDI), and Visual Analog Scale Arm/Neck scores (VAS Arm/Neck).

METHODS

Patient demographics, surgical case characteristics, and motor strength exams were collected in patients who underwent ACDF over a 2-year period. Preoperative weakness was defined by a strength grade ≤3 (on a scale from 0 to 5) in at least one upper extremity muscle group. Multivariate linear regression analysis was performed to determine the effect of the preoperative weakness on HRQOL outcomes.

RESULTS

Of the 276 patients identified, 45 (16.3%) showed evidence of preoperative weakness, 44 (97.8%) of which showed subsequent postoperative motor improvements after ACDF. All patients reported significant improvements in all HRQOL outcome measures. Patients with preoperative weakness reported significantly worse preoperative VAS Arm (6.9 vs. 5.2; p=.01) and VAS Neck (6.1 vs. 4.8; p=.02) pain scores. Compared with patients without preoperative weakness, those with preoperative weakness reported significantly more improvement in NDI (β: -10.9; p=.001). Patients with symptoms greater than or equal to 12 months and preoperative weakness showed significantly less improvement in NDI (β: 14.8; p=.03).

CONCLUSIONS

Patients with preoperative weakness generally exhibited worse pain and HRQOL measures preoperatively, and showed greater potential for improvement after ACDF. Patients with a shorter duration of preoperative weakness had greater potential for improvement in HRQOL measures after ACDF compared with those with longer duration of symptoms. ACDF is an effective procedure to improve strength and HRQOL measures across all patient groups under appropriate indications.

Cervical Spine Endplate Abnormalities and Association With Pain, Disability, and Adjacent Segment Degeneration After Anterior Cervical Discectomy and Fusion

STUDY DESIGN

A retrospective study with prospectively-collected data.

OBJECTIVE

To determine how type, location, and size of endplate lesions on magnetic resonance imaging (MRI) may be associated with symptoms and clinical outcomes after anterior cervical discectomy and fusion (ACDF).

SUMMARY OF BACKGROUND DATA

Structural endplate abnormalities are important, yet understudied, phenomena in the cervical spine. ACDF is a common surgical treatment for degenerative disc disease; however, adjacent segment degeneration/disease (ASD) may develop.

METHODS

Assessed the imaging, symptoms and clinical outcomes of 861 patients who underwent ACDF at a single center. MRI and plain radiographs of the cervical spine were evaluated. Endplate abnormalities on MRI were identified and stratified by type (atypical, typical), location, relation to operative levels, presence at the adjacent level, and size. These strata were assessed for association with presenting symptoms, patient-reported, and postoperative outcomes.

RESULTS

Of 861 patients (mean follow-up: 17.4 months), 57.3% had evidence of endplate abnormalities, 39.0% had typical abnormalities, while 18.2% had atypical abnormalities. Patients with any endplate abnormality had greater odds of myelopathy irrespective of location or size, while sensory deficits were associated with atypical lesions (P = 0.016). Typical and atypical abnormalities demonstrated differences in patient-reported outcomes based on location relative to the fused segment. Typical variants were not associated with adverse surgical outcomes, while atypical lesions were associated with ASD (irrespective of size/location; P = 0.004) and reoperations, when a large abnormality was present at the proximal adjacent level (P = 0.025).

CONCLUSION

This is the first study to examine endplate abnormalities on MRI of the cervical spine, demonstrating distinct risk profiles for symptoms, patient-reported, and surgical outcomes after ACDF. Patients with typical lesions reported worsening postoperative pain/disability, while those with atypical abnormalities experienced greater rates of ASD and reoperation. This highlights the relevance of a degenerative spine phenotypic assessment, and suggests endplate abnormalities may prognosticate clinical outcomes after surgery.

LEVEL OF EVIDENCE

3.

Anterior cervical discectomy and fusion in young adults leads to favorable outcome in long-term follow-up

BACKGROUND CONTEXT

Anterior cervical discectomy and fusion (ACDF) procedures is thought to lead to accelerated degeneration of the adjacent cervical discs and in some cases can be symptomatic (adjacent segment disease, or ASD). The occurrence of ASD is of particular interest when treating young individuals, as the cumulative disease burden may become increasingly significant during their expectedly long lifetime. However, the overall impact of a surgical intervention on the lifetime prognosis of ASD remains unclear.

PURPOSE

Our goal was to study the long-term outcomes of ACDF surgery among those members of the young adult population who have been operated on between the ages of 18 and 40.

STUDY DESIGN

Retrospective study.

PATIENT SAMPLE

All patients between 18 and 40 years of age at the time of surgery who underwent ACDF due to degenerative cervical disorders at Helsinki University Hospital between the years of 1990 and 2005 (476 patients).

OUTCOME MEASURES

Cervical reoperation rate, satisfaction with the surgery, employment status, Neck Disability Index (NDI).

METHODS

We retrospectively analyzed the medical records of all patients between 18 and 40 years of age at the time of surgery who underwent ACDF due to degenerative cervical disorders at Helsinki University Hospital between the years of 1990 and 2005. We sent questionnaires to all available patients at the end of the follow-up (median 17.5 years) to assess their current neck symptoms, general situations, and levels of satisfaction with the surgery. Furthermore, we compared the results for different types of ACDF surgeries (ie, discectomy only vs. synthetic cage or bone autograft implantation for fusion) in propensity-score-matched groups.

RESULTS

Of the 476 patients who were included in the study, surgery was performed in 72% of the cases due to intervertebral disc herniation and in 28% due to spondylotic changes. The total reoperation rate during the entire follow-up (median 17.5 years) was 24%, and 19.5% if early reoperations (<28 days from index surgery) were excluded. At 10 years postsurgery, the total reoperation rate was 16.8% and 12.8% with early reoperations excluded. The probability of surgery for adjacent level disease was 10.3% at 10 years and 16.8% for the duration of the entire follow-up, with the annual incidence rate of 1.1% for those with ASD requiring surgery. Statistically significant risk factors leading to the need for further cervical surgery included central spinal cord compression and smoking at the time of the index operation. After propensity score matching, there was no significant difference found between the outcomes of different types of surgery. A total of 443 patients were still able to be contacted 12-28 years after the surgery. Of the 281 patients responding to the questionnaires, 92% were still satisfied with the results. With respect to employment, 67% of patients were working, 7% were unemployed, and 7% were on disability due to cervical problems. The median NDI score was 12%, with 56% of patients having an NDI score lower than 15%; it has been suggested that this latter NDI score serves as a cut-off value for significant neck morbidity. The NDI scores were significantly higher among female patients, patients with spondylosis, and patients having undergone further cervical surgeries during the follow-up.

CONCLUSIONS

Long-term satisfaction with the surgery was very high, and the employment rate among patients resembled that of the general population in Finland. Thus, the long-term prognosis after having ACDF surgery at a younger age seems to be good, even though nearly half of the patients experienced some persistent neck symptoms later in life.

Risk Factors Associated With Failure to Reach Minimal Clinically Important Difference in Patient-Reported Outcomes Following Anterior Cervical Discectomy and Fusion

Background

The minimum clinically importance difference (MCID) represents a threshold for improvements in patient-reported outcomes (PROs) that patients deem important. No previous study has comprehensively examined risk factors for failure to achieve MCID after anterior cervical discectomy and fusion (ACDF) procedures for radiculopathic symptomatology. The purpose of this study is to determine risk factors for failure to reach MCID for Neck Disability Index (NDI), Visual Analog Scale (VAS) neck pain, and VAS arm pain in patients undergoing 1- or 2-level ACDF procedures.

Methods

A surgical registry of patients who underwent primary, 1- or 2-level ACDF from 2014 to 2016 was reviewed. Rates of MCID achievement for NDI, VAS neck pain, and VAS arm pain at final follow-up were calculated based on published MCID values. Patients were then categorized into demographic and procedural categories. Bivariate regression was used to test for association of demographic and procedural characteristics with failure to reach MCID for each PRO. The final multivariate model including all demographic and procedural categories as controls was created using backward stepwise regression.

Results

Eighty-three, 84, and 77 patients were included in the analysis for VAS neck, VAS arm, and NDI, respectively. Rates of MCID achievement for VAS neck, VAS arm, and NDI were 55.4%, 36.9%, and 76.6%, respectively. On bivariate analysis, patients with Charlson Comorbidity Index (CCI) ≥ 2 were less likely to achieve MCID for NDI than patients with CCI < 2 (P = .025). On multivariate analysis, CCI ≥ 2 (P = .025) was further associated with failure to reach MCID for NDI.

Conclusions

The results of this study suggest that the majority of patients do not reach MCID for arm pain. Additionally, higher comorbidity burden as evidenced by higher CCI scores is a negative predictive factor for the achievement of MCID in neck disability following ACDF.

Level of Evidence

3.

Clinical Outcomes After Four-Level Anterior Cervical Discectomy and Fusion

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

Anterior cervical discectomy and fusion (ACDF) demonstrates reliable improvement in neurologic symptoms associated with anterior compression of the cervical spine. There is a paucity of data on outcomes following 4-level ACDFs. The purpose of this study was to evaluate clinical outcomes for patients undergoing 4-level ACDF.

METHODS

All 4-level ACDFs with at least 1-year clinical follow-up were identified. Clinical outcomes, including fusion rates, neurologic outcomes, and reoperation rates were determined.

RESULTS

Retrospective review of our institutional database revealed 25 patients who underwent 4-level ACDF with at least 1-year clinical follow-up. Average age was 57.5 years (range 38.2-75.0 years); 14 (56%) were male, and average body mass index was 30.2 kg/m² (range 19.9-43.4 kg/m²). Two (8%) required secondary cervical surgery at an average of 94.5 days postoperatively while the remaining 23 did not with an average follow-up of 19 months. Of 23 patients not requiring revision surgery, 16 (69%) patients fused by definition of less than 1 mm of spinous process motion per fused level in flexion and extension. Fifteen (65%) had at least one muscle group with one grade of weakness preoperatively. Nineteen of these patients (83%) had improved to full strength while no patients lost muscle strength.

CONCLUSIONS

Review of our institution's experience demonstrated a low rate of revision cervical surgery for any reason of 8% at mean 19 months follow-up, and neurological examinations consistently improved, despite a high rate of radiographic nonunion (31%).

Short-term outcomes following posterior cervical fusion among octogenarians with cervical spondylotic myelopathy: a NSQIP database analysis

BACKGROUND CONTEXT

Degenerative changes in the cervical spine occur in an age-dependent manner. As the US population continues to age, the incidence of age-dependent, multilevel, degenerative cervical pathologies is expected to increase. Similarly, the average age of patients with cervical spondylotic myelopathy (CSM) will likely trend upward. Posterior cervical fusion (PCF) is often the treatment modality of choice in the management of multilevel cervical spine disease. Although outcomes following anterior cervical fusion for degenerative disease have been studied among older patients (aged 80 years and older), it is unknown if these results extend to octogenarian patients undergoing PCF for the surgical management of CSM.

PURPOSE

The present study aimed to quantify surgical outcomes following PCF for the treatment of CSM among the octogenarian patient population compared with patients younger than 80 years old.

STUDY DESIGN/SETTING

This was a retrospective study that used the National Surgical Quality Improvement Program (NSQIP).

PATIENT SAMPLE

The sample included patients aged 60-89 who had CSM and who underwent PCF from 2012 to 2014.

OUTCOME MEASURES

The outcome measures were multimorbidity, prolonged length of stay (LOS), discharge disposition (to home or skilled nursing/rehabilitation facility), 30-day all-cause readmission, and 30-day reoperation.

METHODS

The NSQIP database was queried for patients with CSM (International Classification of Disease, Ninth Revision, Clinical Modification code 721.1) aged 60-89 who underwent PCF (Current Procedural Terminology code 22600) from 2012 to 2014. Cohorts were defined by age group (60-69, 70-79, 80-89). Data were collected on gender, race, elective or emergent status, inpatientor outpatient status, where patients were admitted from (home vs. skilled nursing facility), American Society of Anesthesiologists class, comorbidities, and single- or multilevel fusion. After controllingfor these variables, logistic regression analysis was used to compare outcome measures in the different age groups.

RESULTS

A total of 819 patients with CSM who underwent PCF (416 aged 60-69, 320 aged 70-79, and 83 aged 80-89) were identified from 2012 to 2014. Of the PCF procedures, 79.7% were multilevel. There were no significant differences in the odds of multimorbidity, prolonged LOS, readmission, or reoperation when comparing octogenarian patients with CSM with patients aged 60-69 or 70-79. Patients aged 60-69 and 70-79 were significantly more likely to be discharged to home than patients over 80 (odds ratio [OR] 4.3, 95% confidence interval [CI] 1.8-10.4, p<.0001, and OR 2.7, 95% CI 1.1-6.4, p=.0005, respectively).

CONCLUSIONS

Compared with patients aged 60-69 and 70-79, octogenarian patients with CSM were significantly more likely to be discharged to a location other than home following PCF. After controlling for patient comorbidities and demographics, 80- to 89-year-old patients with CSM who underwent PCF did not differ in other outcomes when compared with the other age cohorts. These results can improve preoperative risk counseling and surgical decision-making.

The Recovery of Motor Strength after Posterior Percutaneous Endoscopic Cervical Foraminotomy and Discectomy

OBJECTIVE

Cervical radiculopathy infrequently presents with motor weakness. Motor weakness was improved in >90% of patients after anterior cervical discectomy and fusion or posterior cervical foraminotomy. Posterior percutaneous endoscopic cervical foraminotomy and discectomy (PECF) is an alternative surgical technique, but the outcome of motor weakness has not been reported. Our objective was to demonstrate the longitudinal outcomes of motor weakness after PECF.

METHODS

A retrospective review of 106 consecutive patients was performed. Preoperative motor weakness was graded as mild (IV/V strength) or severe (less than III/V strength). The patients visited the outpatient clinic at 1, 3, 6, and 12 months after surgery and yearly thereafter. Improvement was defined as an improved weakness of more than 1 grade, and normalization was defined as the recovery of complete motor strength.

RESULTS

Motor weakness preoperatively presented in 76 of 106 (72%) patients (49%, mild weakness; 23%, severe weakness). After PECF, the weakness improved in 72 of 76 (95%) patients and normalized in 65 of 76 (86%) patients. In the patients with mild weakness, the normalization rates were 48%, 81%, 90%, and 96% at postoperative months 1, 3, 6, and 12, respectively. In the patients with severe weakness, the improvement rates were 50%, 71%, 83%, 88%, and 92%, and the normalization rates were 8%, 38%, 58%, 58%, and 63% at postoperative months 1, 3, 6, 12, and 24, respectively.

CONCLUSIONS

Preoperative motor weakness was improved in 95% of the patients after PECF, but motor weakness was not normalized in 37% of the patients with severe weakness.

Prolonged Preoperative Weakness Affects Recovery of Motor Function After Anterior Cervical Diskectomy and Fusion

INTRODUCTION

Some patients who undergo anterior cervical diskectomy and fusion for radiculopathy or myelopathy demonstrate preoperative weakness. The purpose of this study was to determine which factors predict motor recovery in patients undergoing anterior cervical diskectomy and fusion.

METHODS

A retrospective review of our institutional database identified patients undergoing anterior cervical diskectomy and fusion between 2010 and 2013 with 2 years of clinical follow-up. Patients with substantial weakness, defined as preoperative grade ≤3 (on a scale from 0 to 5) in one or more upper extremity muscle groups, were identified. Regression analysis was used to determine risk factors associated with persistent postoperative weakness.

RESULTS

Of the 1,001 patients who were included, 54 (5.4%) demonstrated substantial weakness. By 2 years postoperatively, 47 of 54 patients (87%) demonstrated motor recovery. The duration of preoperative weakness was an independent predictor of recovery (median, 4 months of preoperative weakness among patients with recovery versus 10 months in patients with persistent weakness; P = 0.012).

DISCUSSION

Duration of preoperative motor weakness is an independent predictor of motor recovery after anterior cervical diskectomy and fusion in patients with substantial motor weakness.

CONCLUSION

Patients being considered for anterior cervical diskectomy and fusion who have substantial preoperative motor deficits may benefit from earlier surgical intervention.

Cervical radiculopathy

Cervical radiculopathy is a common clinical scenario. Patients with radiculopathy typically present with neck pain, arm pain, or both. We review the epidemiology of cervical radiculopathy and discuss the diagnosis of this condition. This includes an overview of the pertinent findings on the patient history and physical examination. We also discuss relevant clinical syndromes that must be considered in the differential diagnosis including peripheral nerve entrapment syndromes and shoulder pathology. The natural history of cervical radiculopathy is reviewed and options for management are discussed. These options include conservative management, non-operative modalities such as physical therapy, steroid injections, and operative intervention. While the exact indications for surgical intervention have not yet been elucidated, we provide an overview of the available literature regarding indications and discuss the timing of intervention. The surgical outcomes of anterior cervical decompression and fusion (ACDF), cervical disc arthroplasty (CDA), and posterior cervical foraminotomy (PCF) are discussed.

Anterior Cervical Discectomy and Fusion with Stand-Alone Trabecular Metal Cages as a Surgical Treatment for Cervical Radiculopathy: Mid-Term Outcomes

Study Design

Retrospective case cohort study done between 2002 and 2012.

Purpose

To assess the mid-term clinical and radiological outcomes of 1-level and 2-level anterior cervical discectomy and fusion (ACDF) with stand-alone trabecular metal cages.

Overview of Literature

ACDF is the gold standard surgical treatment for cervical degenerative disease. The usual surgical practice is to use an anteriorly placed fusion plate with or without interdiscal cages.

Methods

Patients between 36 and 64 years of age diagnosed with cervical radiculopathy who underwent ACDF using stand-alone trabecular metal cages with at least 3 years follow-up were included in this study. Recorded clinical outcomes included residual axial neck pain, radicular arm pain, upper extremity weakness, and upper extremity altered sensation. Visual Analogue scores were also recorded. Fusion was assessed by lateral radiographs looking for bone breaching and radiolucent lines around the device at the latest follow-up.

Results

Ninety patients were included in the study. Fifty-one patients underwent 2-level surgery and 39 patients underwent 1-level surgery. Mean age was 44±10.4 years and mean follow-up time was 4.5±2.6 years. Patients reported excellent or good outcomes (90%), as well as improvements in axial neck pain (80%), radicular arm pain (95%), upper extremity weakness (85%), and upper extremity altered sensation (90%). Most patients (90%) progressed to fusion at the 1-year follow-up. The reoperation rate was 3.6%. There was no reported persistent dysphagia, voice complaints, dural tear, or tracheal or oesophageal perforation in any of the patients. One patient developed a deep methicillin-resistant Staphylococcus aureus infectious infarction of the spinal cord, which was treated with antibiotics. Recovery was complete at the 1-year follow up.

Conclusions

Mid-term results show that surgical treatment with ACDF with trabecular metal cages is a safe and effective treatment of single and 2-level cervical disc radiculopathy and neck pain.

Impact of over distraction on occurrence of axial symptom after anterior cervical discectomy and fusion

OBJECTIVE

A retrospective review was undertaken to evaluate the impact of over distraction on cervical axial symptoms (AS) after anterior cervical discectomy and fusion (ACDF).

METHODS

The retrospective review included 421 patients who underwent ACDF for one or two segments. Of these, 78 patients for whom complete follow-up data were available were selected for inclusion in the analysis. X-rays of the cervical vertebra were performed immediately after the surgery, 3 months postsurgery, and at a final follow up (6-24 months). According to the presence/absence of AS, the patients were divided into a symptom group (Group S) and a nonsymptom group (Group N). The ratio of intervertebral height change, change in the overall cervical curvature, change in the local curvature of the surgical segment, cervical total range of motion (ROM), and Japanese Orthopaedic Association (JOA) recovery rate were compared and analyzed. A linear regression analysis of the ratio of intervertebral height change and the symptom and severity of the AS according to the Visual Analogue Scale (VAS) was carried out.

RESULTS

The total incidence of AS was 33.97%. C5 nerve root palsy occurred in one case in Group S after the surgery. The neurologic symptoms of both groups were significantly alleviated after the surgery. The ratio of intervertebral height change in Group S was significantly higher than that in Group N at the last follow-up (P < 0.05). However, the changes in the overall cervical curvature, local curvature of the surgical segment, cervical ROM, and JOA recovery rates were not statistically significant (P > 0.05). In Group S, 37% of the patients had symptoms that occurred in the chest area, and the ratio of intervertebral height change was significantly positively correlated with the VAS score of the AS (r = 0.893).

CONCLUSIONS

The occurrence of postoperative AS will significantly increase if the ratio of intervertebral height change of the surgical segment after ACDF is over 10%.