Preoperative Modic changes are related to axial symptoms after anterior cervical discectomy and fusion

Modic Changes in Patients Who Have Undergone Anterior Cervical Discectomy and Fusion: The Correlation With Fusion Success and Subsidence

OBJECTIVE

There is a lack of research on modic change (MC) in the cervical spine, especially regarding its impact on patients following anterior cervical discectomy and fusion (ACDF). Some researchers strongly believe that MC may affect the prognosis after anterior cervical surgery. Thus, this study aimed to assess MC in patients who underwent ACDF, investigating its incidence, risk factors, and correlation with fusion success and subsidence rate.

METHODS

We retrospectively reviewed 154 patients who underwent single-level ACDF from January 2010 to December 2020, with a minimum follow-up of 12 months. Preoperative and postoperative clinical and radiological parameters were recorded at pre-operation, 1 week, 3 months after operation, and the last follow-up. The primary outcomes were the fusion rate and cage subsidence. Radiological measurements, including overall (Cobb C) and segmental cervical angle (Cobb S), anterior disc height (ADH), and posterior disc height (PDH) were also recorded. The independent t-test or Mann-Whiteny U test was used to compare continuous data, and categorical variables were assessed using the Pearson's chi-square test of Fisher's exact test. Logistic regression analysis was also adopted to distinguish corresponding factors related with the progress of MC.

RESULTS

Of the 154 patients, the incidence of MC was 44.2% (68/154). The group with MC showed a larger proportion of males and osteoporosis. The fusion rate of those with MC was 88.2% (60/68) while that in the non-MC group was 97.7% (84/86, p = 0.02). The MC group presented a subsidence rate of 27.9%, which was substantially higher than in the non-MC group (9.3%, p < 0.01). NDI and VAS neck was significantly higher in the MC group than in the non-MC group (p = 0.014; p = 0.039). Sex and osteoporosis were distinguished as independent factors related to MC by regression analysis (p = 0.006; p = 0.026).

CONCLUSION

Preoperative MC could adversely hinder the fusion process and may increase the incidence of subsidence, affecting clinical outcomes of those underwent ACDF. Patients with MC, especially type 1 MC, are more easily suffered from neck pain than those without MC. Male sex and osteoporosis were risk factors for MC. In order to achieve a better bony fusion and avoid cage subsidence in those with MC, we encourage patients to prolong their immobilization duration with a cervical collar and precisely manage osteoporosis during the peri-operative period.

Development and validation of a predictive model for the risk of symptomatic adjacent segmental degeneration after anterior cervical discectomy and fusion

Background

To investigate the risk factors for symptomatic adjacent segment degeneration (ASD) 5 years after anterior cervical discectomy and fusion (ACDF) and develop and evaluate predictive models.

Methods

A total of 655 patients who underwent ACDF were randomly assigned to the training set (n = 393) or validation set (n = 262) at a ratio of 6:4. Independent predictors of ASD were selected by LASSO regression and logistic regression analysis. A calibration curve, ROC curve and DCA curve were used to evaluate the model performance.

Results

LASSO regression combined with logistic regression analysis revealed that age, cervical canal stenosis, smaller T1S and smaller cervical lordosis (CL) were risk factors for ASD 5 years after surgery. Nomographic analysis using appeal factors was used to predict the risk of ASD. The area under the ROC curve was 0.711 (95% CI: 0.643-0.780) in the training set and 0.701 (95% CI: 0.618-0.785) in the validation set. The calibration curve showed no significant bias in either set. The DCA indicated that using the nomogram to predict the risk of ASD would be more accurate when the risk threshold probability was 12-53% in the training set and 6-43% in the validation set.

Conclusion

Age, cervical spinal stenosis, a smaller T1S, and a smaller CL are independent risk factors for ASD 5 years after ACDF surgery. Based on these four indicators, we constructed a new clinical prediction model that has a certain predictive effect and is conducive to clinical decision-making and treatment planning.

Prevalence, risk factors, natural history, and prognostic significance of Modic changes in the cervical spine: a comprehensive systematic review and meta-analysis of 12,754 participants

OBJECTIVE

Modic changes (MCs) in the cervical spine are common, but remain an under-researched phenomenon, particularly regarding their prevalence, natural history, risk factors, and implications for surgical outcomes. This systematic review and meta-analysis endeavors to elucidate the multifactorial dimensions and clinical significance of cervical MCs.

METHODS

Following PRISMA guidelines, a comprehensive systematic search was performed using Medline (via PubMed), EMBASE, Scopus, and Web of Science databases from their dates of inceptions to September 4, 2023. All identified articles were meticulously screened based on their relevance to our investigative criteria. Bias was assessed using quality assessments tools, including Quality in Prognosis Studies (QUIPS) and Newcastle-Ottawa Scale (NOS). Diverse datasets encompassing MCs prevalence, demographic influences, risk factors, cervical sagittal parameters, and surgical outcomes were extracted. Meta-analysis using both random and common effects model was used to synthesis the metadata.

RESULTS

From a total of 867 studies, 38 met inclusion criteria and underwent full-text assessment. The overall prevalence of cervical MCs was 26.0% (95% CI: 19.0%, 34.0%), with a predominance of type 2 MCs (15% ; 95% CI: 0.10%, 0.23%). There was no significant difference between MCs and non-MCs in terms of neck pain (OR:3.09; 95% CI: 0.81, 11.88) and radicular pain (OR: 1.44; 95% CI: 0.64, 3.25). The results indicated a significantly higher mean age in the MC group (MD: 1.69 years; 95% CI: 0.29 years, 3.08 years). Additionally, smokers had 1.21 times the odds (95% CI: 1.01, 1.45) of a higher risk of developing MCs compared to non-smokers. While most cervical sagittal parameters remained unaffected, the presence of MCs indicated no substantial variation in pain intensity. However, a significant finding was the lower Japanese Orthopaedic Association (JOA) scores observed in MC patients at the 3-month (MD: -0.34, 95% CI: -0.62, -0.07) and 6-month (MD: -0.40, 95% CI: -0.80, 0.00) postoperative periods, indicating a prolonged recovery phase.

CONCLUSION

This study found a predominant of type 2 MCs in the cervical spine. However, there was no significant mean difference between MCs and non-MC groups regarding neck pain and radicular pain. The results underscore the necessity for expansive, longitudinal research to elucidate the complexity of cervical MCs, particularly in surgical and postoperative contexts.

Correlation between axial symptoms and cervical sagittal alignment parameters in patients with two-level or three-level cervical spondylotic myelopathy: anterior cervcial discectomy and fusion versus hybird surgery

OBJECTIVE

To comparatively analyze the correlation between axial symptoms (AS) and cervical sagittal alignment parameters after anterior cervical discectomy and fusion (ACDF) and hybrid surgery (HS).

METHODS

From January 2018 to June 2023, 74 patients who underwent ACDF (n = 36) or HS (n = 38) for two-level or three-level cervical spondylotic myelopathy were retrospectively analyzed. The Visual Analogue Scale (VAS), Japanese Orthopedic Association (JOA), Neck Disability Index (NDI) were recorded to assess clinical outcomes. Cervical sagittal alignment parameters (Cobb's angle C2-7, C7 slope [C7S], and C2-7 sagittal vertical axis [C2-7 SVA]) were measured preoperatively, 3 days postoperatively, and at the last follow-up. The range of motion (ROM) of C2-7 and ROM of surgical segment were measured. The occurrence of AS was observed at the last follow-up. Logistic regression was used to analyze the correlation between postoperative AS and cervical sagittal alignment parameters.

RESULTS

Both in ACDF group and HS group, VAS, JOA and NDI scores showed significant improvements at 3-day postoperation and at the last follow-up (P < 0.05). However, there was no significant difference between the two groups (P > 0.05). The Cobb's angle C2-7 and C7S were significantly increased at 3 days postoperation compared with pre-operatively in both groups (P < 0.05). C2-7SVA was increased in both groups 3 days after surgery compared with pre-operatively, but there was no significant difference (P > 0.05). At the last follow-up, the ROM of C2-7 in ACDF group was significantly smaller than HS group (P < 0.05). The prevalence of postoperative AS in the ACDF group and HS group was 41.7 and 18.4%, respectively, with statistical difference between the two groups (P < 0.05). When simple Logistic regression analysis was used, the last Cobb's angle C2-7 (β = -0.088), the last C2-7SVA (β = 0.099) in ACDF group and the last C2-7SVA (β = 0.222) in HS group were all correlated with the occurrence of postoperative AS. When multiple Logistic regression analysis was used, only the last C2-7SVA (β = 0.181) in the HS group was positively correlated with the occurrence of postoperative AS.

CONCLUSIONS

Both ACDF and HS can achieve satisfied clinical outcomes. ACDF and HS can improve cervical sagittal balance to a certain extent, and HS is superior to ACDF in maintaining ROM. The decrease of the last Cobb's angle C2-7 and the increase of the last C2-7SVA may be related to the occurrence of AS after ACDF. The increase of the last C2-7SVA was an independent risk factor for the occurrence of AS after HS.

Cervical alignment and clinical outcome of anterior cervical discectomy and fusion vs. anterior cervical corpectomy and fusion in local kyphotic cervical spondylotic myelopathy

Background

Cervical local kyphosis (CLK) is a common degenerative disorder with a potentially debilitating and intractable condition. Currently, there is still debate on the optimal treatment of local kyphotic cervical spondylotic myelopathy (LKCSM) via different anterior approaches.

Objective

The objective of this study was to evaluate the surgical efficacy of anterior cervical discectomy and fusion (ACDF) vs. anterior cervical corpectomy and fusion (ACCF) for the treatment of LKCSM. In addition, the cervical sagittal alignment parameters and axial symptoms (AS) severity after CLK correction were analyzed.

Materials and methods

From January 2016 and December 2020, 104 patients who suffered LKCSM were retrospectively reviewed. These patients underwent ACDF (n = 53) and ACCF (n = 51). Pre- and postoperatively, cervical sagittal alignment parameters were measured on the lateral X-rays, including local kyphotic angles (LKA), C2-7 Cobb angle, T1 slope, and C2-7 sagittal vertical axis (C2-7 SVA). The neurological recovery rate was calculated according to the Japanese Orthopedic Association (JOA) score. The AS severity was evaluated using Neck Disability Index (NDI).

Results

Significant differences (P < 0.05) were demonstrated between ACDF and ACCF groups regarding LKA, LKA correction, C2-7 Cobb angle, T1 slope, C2-7 SVA, NDI, NDI recovery and NDI ranking system. However, no significant differences (P > 0.05) existed in JOA score, recovery rate, and neurological recovery rate grade. In both groups, significant differences (P < 0.05) were demonstrated between pre- and postoperative LKA, T1 slope, C2-7 Cobb angle, C2-7 SVA, JOA score, and NDI. LKA correction showed the positive correlations with the recovery rate (r = 0.48, P < 0.001), and with the NDI recovery in ACDF group (r = 0.49, P < 0.001) and in ACCF group (r = 0.55, P < 0.001).

Conclusions

LKCSM with ≤3 segments of spinal cord compression can be improved with either ACDF or ACCF, resulting in satisfactory neurological outcomes. CLK correction can significantly improve the neurological function and AS, and increase the T1 slope and C2-7 SVA. However, ACDF was more favorable than ACCF in the CLK correction.

Endplate abnormalities, Modic changes and their relationship to alignment parameters and surgical outcomes in the cervical spine

Modic changes (MC) and endplate abnormalities (EA) have been shown to impact preoperative symptoms and outcomes following spinal surgery. However, little is known about how these phenotypes impact cervical alignment. This study aimed to evaluate the impact that these phenotypes have on preoperative, postoperative, and changes in cervical alignment in patients undergoing anterior cervical discectomy and fusion (ACDF). We performed a retrospective study of prospectively collected data of ACDF patients at a single institution. Preoperative magnetic resonance imagings (MRIs) were used to assess for the MC and EA. Patients were subdivided into four groups: MC-only, EA-only, the combined Modic-Endplate-Complex (MEC), and patients without either phenotype. Pre and postoperative MRIs were used to assess alignment parameters. Associations with imaging phenotypes and alignment parameters were assessed, and statistical significance was set at p < 0.5. A total of 512 patients were included, with 84 MC-only patients, 166 EA-only patients, and 71 patients with MEC. Preoperative MC (p = 0.031) and the MEC (p = 0.039) had significantly lower preoperative T1 slope compared to controls. Lower preoperative T1 slope was a risk factor for MC (p = 0.020) and MEC (p = 0.029) and presence of MC (Type II) and the MEC (Type III) was predictive of lower preoperative T1 slope. There were no differences in postoperative alignment measures or patient reported outcome measures. MC and endplate pathologies such as the MEC appear to be associated with worse cervical alignment at baseline relative to patients without these phenotypes. Poor alignment may be an adaptive response to these degenerative findings or may be a risk factor for their development.

Cervical alignment and clinical outcome of anterior decompression with fusion vs. posterior decompression with fixation in kyphotic cervical spondylotic myelopathy

Background context

Cervical kyphosis is a common but potentially debilitating and challenging condition. There is controversy on the optimal surgical strategy for the treatment of kyphotic cervical spondylotic myelopathy (KCSM) using either anterior approach or posterior approach.

Introduction

The purpose of this study was to investigate the surgical efficacy of anterior decompression with fusion (ADF) vs. posterior decompression with fixation (PDF) for the treatment of KCSM, and to further analyze the changes of cervical spinal alignment parameters and axial symptoms (AS) severity after kyphotic correction.

Materials and methods

We retrospectively reviewed 117 patients with KCSM who had undergone ADF (58 patients) and PDF (59 patients) between January 2016 and December 2020. Cervical spinal alignment parameters, including curvature index (CI) and C2-7 Cobb angle, were measured on the PreOP and PostOP lateral radiographs. Recovery rate was calculated based on the Japanese Orthopedic Association (JOA) score. AS severity was quantified by Neck Disability Index (NDI). A P-value less than 0.05 was considered to be significant.

Results

The patient mean age, gender, presenting symptoms and follow-up time were similar between the two groups (P > 0.05). However, there were statistically significant differences (P < 0.001) between the two groups regarding the operation levels, operating time and intraoperative blood loss. Analysis of PostOP follow-up data showed significant differences (P < 0.001) in CI, correction of CI, C2-7 Cobb angle, and NDI between the two groups, whereas no significant differences in JOA score (P = 0.16) and recovery rate (P = 0.14). There were significant differences (P < 0.001) in CI, C2-7 Cobb angle, JOA score, and NDI between PreOP and PostOP follow-up in each group. Correction of CI showed positive correlation with recovery of NDI in Group ADF (r = 0.51, P < 0.001), and in Group PDF (r = 0.45, P < 0.001).

Conclusion

Satisfied neurological improvement was obtained by ADF and PDF for patients with KCSM. Cervical kyphotic correction caused significant improvement of AS, and was more favorable with ADF than with PDF. Surgeons should pay full consideration of the merits and shortcomings of each approach when deciding on a surgical plan.

Ultrafast cervcial spine MRI protocol using deep learning-based reconstruction: Diagnostic equivalence to a conventional protocol

PURPOSE

A major drawback of magnetic resonance imaging (MRI) is its limited imaging speed. This study proposed an ultrafast cervical spine MRI protocol (2 min 57 s) using deep learning-based reconstruction (DLR) and compared the diagnostic results to those of conventional MRI protocols (12 min 54 s).

METHODS

Fifty patients who underwent cervical spine MRI using both conventional and ultrafast protocols, including sagittal T1-weighted, T2-weighted, short-TI inversion recovery, and axial T2*-weighted imaging were included in this study. The ultrafast protocol shortened the acquisition time to approximately-one-fourth of that of the conventional protocol by reducing the phase matrix, oversampling rate, and number of excitations, and by applying compressed sensing. To compensate for the decreased signal-to-noise ratio caused by acceleration, noise reduction using DLR was performed. For image interpretation, three neuroradiologists graded or classified degenerative changes, including central canal stenosis, foraminal stenosis, endplate degeneration, disc degeneration, and disc hernia. The presence of other pathologies was also recorded. Given the absence of a reference standard, we tested the interchangeability of the two protocols by calculating the 95% confidence interval (CI) of the individual equivalence index. We also assessed the inter-protocol intra-reader agreement using kappa statistics.

RESULTS

Except for endplate degeneration, the 95 % CI of the individual equivalence index for all variables did not exceed 5 %, indicating interchangeability between the two protocols. The kappa values ranged from 0.600 to 0.977, indicating substantial to almost perfect agreement.

CONCLUSIONS

The proposed ultrafast MRI protocol yielded almost equivalent diagnostic results compared as the conventional protocol.

Evaluating the Impact of Modic Changes on Operative Treatment in the Cervical and Lumbar Spine: A Systematic Review and Meta-Analysis

Modic changes (MCs) are believed to be potential pain generators in the lumbar and cervical spine, but it is currently unclear if their presence affects postsurgical outcomes. We performed a systematic review in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. All studies evaluating cervical or lumbar spine postsurgical outcomes in patients with documented preoperative MCs were included. A total of 29 studies and 6013 patients with 2688 of those patients having preoperative MCs were included. Eight included studies evaluated cervical spine surgery, eleven evaluated lumbar discectomies, nine studied lumbar fusion surgery, and three assessed lumbar disc replacements. The presence of cervical MCs did not impact the clinical outcomes in the cervical spine procedures. Moreover, most studies found that MCs did not significantly impact the clinical outcomes following lumbar fusion, lumbar discectomy, or lumbar disc replacement. A meta-analysis of the relevant data found no significant association between MCs and VAS back pain or ODI following lumbar discectomy. Similarly, there was no association between MCs and JOA or neck pain following ACDF procedures. Patients with MC experienced statistically significant improvements following lumbar or cervical spine surgery. The postoperative improvements were similar to patients without MCs in the cervical and lumbar spine.

Intervertebral-spreader-assisted anterior cervical discectomy and fusion prevents postoperative axial pain by alleviating facet joint pressure

Objective

To evaluate the relationship of postoperative cervical axial pain with different vertebral distraction methods used during ACDF procedures in cervical spondylosis patients.

Methods

Ninety-four single-level cervical spondylotic myelopathy patients with significantly loss of intervertebral disc height who underwent ACDF surgery in our institute between January 2018 and January 2020 were enrolled. Cervical spine lateral radiographs were taken preoperatively, 3 days, 1-month, 2-month and 6-month after the surgery. The intervertebral disc height (IDH), interfacet distance (IFD), JOA (Japanese Orthopaedic Association) score, NDI (Neck Disability Index) score, nVAS (Neck Visual Analogue Scale) score and aVAS (Arm Visual Analogue Scale) score were measured. The correlation of clinical parameters and intervertebral disc height was evaluated. Then the correlation of clinical outcomes and different distraction method was evaluated. The patients were randomly divided into two groups, one uses Casper pin distractor system alone for distraction (Caspar alone group) and the other uses spreader assisted distraction method (Casper + spreader group). In biomechanical study, four cervical spine cadavers were selected for facet pressure measurements under different vertebral distraction methods, and the facet joint pressure was measured using force sensors.

Results

Satisfactory cervical fusion and neurological recovery were achieved in all patients. No significant correlation of IDH, IFD, JOA, NDI or aVAS with nVAS score was found. No significant difference between the change in disc height and clinical outcomes was found. However, by comparing the clinical parameters of patients in different vertebral distraction groups, we found significant changes in the early nVAS and NDI scores (P = 0.11, P = 0.48) of the Casper + spreader group (3 days postoperation), and was associated with a better nVAS score at 2 months postoperation (P < 0.05). The biomechanical study in cervical cadavers also showed significantly and continuously decreased facet joint pressure in the spreader assisted vertebral distraction group (P < 0.01).

Conclusions

Spreader-assisted vertebral distraction method effectively alleviates postoperative neck pain in degenerative cervical spondylosis patients treated with ACDF. The mechanism may be related to the transient relief of facet joint pressure during the vertebral distraction procedure in ACDF.

The Modic-endplate-complex phenotype in cervical spine patients: Association with symptoms and outcomes

This study describes a novel, combined Modic changes (MC) and structural endplate abnormality phenotype of the cervical spine, which we have termed the Modic-Endplate-Complex (MEC), and its association with preoperative symptoms and outcomes in anterior cervical discectomy and fusion (ACDF) patients. This was a retrospective study of prospectively collected data at a single institution. Preoperative cervical magnetic resonance imagings were used to assess the presence of MC and endplate abnormalities. Patients were divided into four groups: MC-only, endplate abnormality-only, the MEC and controls. The MEC was defined as the presence of both a MC and endplate abnormality in the cervical spine. Phenotypes were further stratified by location and compared to controls. Associations with patient-reported outcome measures were assessed using regression controlling for baseline characteristics. A total of 628 patients were included, with 84 MC-only, 166 endplate abnormality-only, and 187 MEC patients. Both MC (p < 0.001) and endplate abnormalities (p < 0.001) were independently associated with one another. MC at the adjacent level (p = 0.018), endplate abnormalities (regardless of location) (p = 0.001), and the MEC within the fusion segment (p = 0.027) were all associated with higher Neck Disability Index scores. Both MC within the fusion segment (p = 0.008) and endplate abnormalities within the fusion segment (p = 0.017) associated with lower Veteran's Rand 12-item scores. MC and structural endplate abnormalities commonly manifest concomitantly in patients indicated for ACDF for degenerative pathology. Patients with the endplate pathology, including the MEC phenotype, reported significantly higher levels of postoperative disability following ACDF. These findings add valuable data to the prognostic assessment of degenerative cervical spine patients.

Risk Factors for Axial Symptoms After Anterior Surgery Treating for Multilevel Cervical Disorder with kyphosis

STUDY DESIGN

A retrospective study.

OBJECTIVE

The aim of this study was to investigate the risk factors associated with axial symptoms (AS) after anterior surgery in treatment of multilevel cervical disorder with kyphosis based on subgroup of follow-up time.

SUMMARY OF BACKGROUND DATA

Although many scholars reported on AS after cervical surgery, the risk factors associated with AS are controversial. Few studies have investigated the risk factors of AS after anterior cervical surgery treating multilevel cervical disorder with kyphosis.

METHODS

Totally, 103 patients who suffered from multilevel cervical disorder with kyphosis receiving anterior surgery from July 2015 to June 2017 were reviewed for clinical and radiological outcomes. These data were collected at the time of before surgery, 1 week, 3 months, 6 months, 1 year, and 2 years after surgery. Data were performed to compare between the patients with and without AS.

RESULTS

In our study, the occurrence of AS was 46.6%, 34.0%, 20.4%, 12.6%, and 10.7% at the time of 1 week, 3 months, 6 months,1 year, and 2 years after surgery, respectively. Our findings showed that patients with smoking, disease duration, preoperative Modic changes (Mcs), post-operative Cobb angle of C2-7, cervical range of motion (ROM) and T1 slope, and change of Cobb angle of C2-7, cervical ROM and T1 slope were associated with AS within 1 year after surgery. However, patients with smoking and preoperative Mcs were found to be risk factors associated with AS at at any follow-up.

CONCLUSION

In the present study, many factors were related to AS during 1-year after surgery. What's more, patients with smoking and preoperative Mcs were associated with AS at any follow-up. We hope this article can provide a reference for spinal surgeons to predict which patients were susceptible to suffer from AS after anterior surgery in treatment of multilevel cervical disorder with kyphosis.Level of Evidence: 3.

Biomechanical Effect of C5 /C6 Intervertebral Reconstructive Height on Adjacent Segments in Anterior Cervical Discectomy and Fusion - A Finite Element Analysis

OBJECTIVE

To investigate the biomechanical effect of different intervertebral reconstructive heights on adjacent segments following C₅ /C₆ anterior cervical discectomy and fusion (ACDF) through finite element analysis.

METHODS

A finite element model of intact C₄ -C₇ segments was developed and validated for the present study. Five additional C₄ -C₇ postoperative models were constructed with 100%, 125%, 150%, 175%, and 200% of the benchmark height of C₅ /C₆ on the basis of the intact model. The changes in intradiscal pressure (IDP) and range of motion (ROM) of adjacent segments before and after reconstruction of C₅ /C₆ were analyzed.

RESULTS

For the upper adjacent segment (C₄ /C₅ ), the IDPs under the different loading conditions all increased after reconstruction. The maximum IDPs were 0.387, 0.489, 0.491, and 0.472 MPa under flexion, extension, axial rotation, and lateral bending, respectively, observed at the reconstructive height of 200%. The minimum IDPs were observed at 150% reconstructive height under all loading conditions except extension, and were 57, 86 and 81% of the maximum IDPs under flexion, axial rotation, and lateral bending, respectively. The minimum IDP under extension occurred when the reconstructive height is 125% of the benchmark height. For the lower adjacent segment (C₆ /C₇ ), the IDPs of postoperative models under all loading conditions also increased compared to the preoperative model. The maximum IDPs after reconstruction under flexion, extension, axial rotation, and lateral bending were 0.402, 0.411, 0.461, and 0.497 MPa, respectively, when the height of the reconstruction was 200% of the benchmark. The minimum IDPs were observed after a reconstruction at 150% of the benchmark, and were 59%, 85%, 82%, and 81% of the maximum IDPs under flexion, extension, axial rotation, and lateral bending loading conditions.

CONCLUSIONS

The reconstructive height is an important factor affecting the IDP and the ROM of adjacent segments after ACDF. To delay the adjacent segment disease, an intervertebral reconstructive height of 150% is an appropriate height in C₅ /C₆ ACDF.

Association between Modic changes, disc degeneration, and neck pain in the cervical spine: a systematic review of literature

BACKGROUND

The contribution of Modic changes (MCs) in relation to spinal pain and degenerative changes has been evaluated frequently. However, most studies focus on lumbar spine. The association between MCs, neck pain, and cervical disc degeneration is not clear.

PURPOSE

The objective of this study was to review current literature on the association between MCs, cervical disc degeneration, and neck pain.

STUDY DESIGN

A systematic review METHODS: A literature search was performed in PubMed, Embase, and Web of Science using a sensitive search string combination. Studies were selected by predefined selection criteria and risk of bias was assessed using a validated Cochrane Checklist adjusted for this purpose.

RESULTS

Fourteen articles that associated MCs with neck pain and/or cervical disc degeneration were included in the present study. Ten articles showed low risk of bias and four showed intermediate risk of bias. The prevalence of MCs in cervical spine varied from 5% to 40% and type II was predominant. Patients with MCs were reported to experience more neck pain and disability. Cervical disc degeneration was detected more frequently in patients with MCs.

CONCLUSIONS

Modic changes were found to be associated with neck pain and with disc degeneration. Therefore, the large variation in prevalence that is reported is highly dependent on the nature of the studied population.

The Impact of Modic Changes on Preoperative Symptoms and Clinical Outcomes in Anterior Cervical Discectomy and Fusion Patients

Objective

To assess the impact of Modic changes (MC) on preoperative symptoms, and postoperative outcomes in anterior cervical discectomy and fusion (ACDF) patients.

Methods

We performed a retrospective study of prospectively collected data of ACDF patients at a single institution. Preoperative magnetic resonance imagings were used to assess the presence of MC. MC were stratified by type and location, and compared to patients without MC. Associations with symptoms, patient-reported measures, and surgical outcomes were assessed.

Results

A total of 861 patients were included, with 356 patients with MC (41.3%). MC more frequently occurred at C5–6 (15.1%), and type II was the most common type (61.2%). MC were associated with advanced age (p < 0.001), more levels fused (p < 0.001), a longer duration of symptoms, but not with specific symptoms. MC at C7–T1 resulted in higher postoperative disability (p < 0.001), but did not increase risk of adjacent segment degeneration or reoperation.

Conclusion

This study is the first to systematically examine the impact of cervical MC, stratified by type and location, on outcomes in ACDF patients. Patients with MC were generally older, required larger fusions, and had longer duration of preoperative symptoms. While MC may not affect specific outcomes following ACDF, they may indicate a more debilitating preoperative state for patients.

Is the bone fusion affected by Modic-2 changes in single-level anterior cervical discectomy and fusion?

To explore the impact of Modic changes (MCs) on bone fusion after single-level anterior cervical discectomy and fusion (ACDF) with a zero-profile implant (the Zero-P implant system).From November 2014 to November 2017, a total of 116 patients who underwent single-level ACDF with the Zero-P implant were divided into two groups according to MRI showing type 2 MCs (MC2) or no MCs (i.e., the MC2 group and the NMC group, respectively). A total of 92 (79.3%) patients were classified into the NMC group, and 24 (20.7%) patients were classified into the MC2 group. The clinical outcomes and fusion rates were retrospectively evaluated between the 2 groups preoperatively and postoperatively at 3, 6, and 12 months, and the final follow-up.The Japanese Orthopedic Association (JOA) scores and the visual analogue scale (VAS) scores of neck pain were significantly improved compared to the preoperative scores in both the NMC and MC2 groups (P < .05). However, there were no differences in JOA or VAS scores between the 2 groups (P > .05). The fusion rates of the NMC and MC2 groups at 3, 6, and 12 months postoperatively, and the final follow-up were 33.7% and 12.5%, 77.2% and 54.2%, 89.1% and 87.5%, and 97.8% and 95.8%, respectively. The fusion rates were significantly lower at 3 and 6 months after surgery in the MC2 group than in the NMC group (P < .05).The presence of MC2 did not affect the clinical outcome but delayed the fusion time following ACDF with the Zero-P implant system.Level of Evidence is Level 3.

Analysis of Correlation Between Age and Cervical Facet Joint Degeneration and Modic Changes in Patients with Cervical Spondylotic Myelopathy

Background

Because facet joints move with the disc, changes in vertebral bodies occur simultaneously with progression of degeneration of cervical facet joints. This study investigated age-related differences in cervical facet joint abnormalities and multi-dimensional characteristics of MCs in patients with cervical spondylotic myelopathy.

Material/Methods

Forty-five patients underwent both magnetic resonance imaging (MRI) and computed tomography (CT) of the cervical spine. Axial and sagittal parameter changes from C3 to C7, including facet orientation (FO) and facet tropism (FT), and Modic changes (MCs), were evaluated and documented preoperatively, and we also measured the heights and diameters of MCs and performed correlation analysis and established linear regression models.

Results

The axial facet orientation increased slightly from C3 66.5 (11.4) to C7 89.9 (19). The sagittal facet orientation and facet tropism increased between C3–C4 and C6–C7, but it decreased between C4 to C6. The MCs volume decreased from C3 to C4 and increased from C4 to C7. There was a gradual decrease of FO and FT from C3 to C5 and a gradual increase of these 2 angles from C5 to C7 in all age groups. The lowest values of FO and FT were detected at C5, while the highest values of FO and FT were detected at C7.

Conclusions

Age was negatively correlated with the axial, sagittal, and coronal cervical facet orientation, especially at C4/5 level. The FT with respect to the axial and sagittal plane from C5 to C6 increased with age.