The course of Modic vertebral body changes after posterolateral lumbar fusion on fused and adjacent levels: A systematic review of the literature

Contribution of MRI and imaging exams in the diagnosis of lumbar pseudarthrosis

INTRODUCTION

The diagnosis of pseudoarthrosis is based on imaging and clinical exam findings. The standard for pseudarthrosis diagnosis remains postoperative observation through computer tomography (CT) and patient's symptoms. This can be further augmented by dynamic X-ray imaging or nuclear positron emission tomography (PET) CT to demonstrate an absence of fusion by showing a persistence of mobility. However, there is not a uniform diagnostic approach that is a standard of care amongst spine practioners. The aim of this study is to describe the timeline and diagnostic analysis for pseudoarthrosis between the initial surgery and follow-up procedure.

METHODS

This is a single-center retrospective observational study. The aim was to enroll patients reoperated for pseudarthrosis after 1 or 2 level lumbar fusions, between August 1st, 2008 and August 1st, 2018. The exams were reviewed by one surgeon and one radiologist, defining a status either in favor of pseudarthrosis, or against it, or inconclusive, based on the radiological criteria mentioned below. We then investigated different combinations of exams and their specific chronology before a diagnosis was established.

RESULTS

Forty-four patients were included, 70.5% male and with a mean age of 47.3 years. The median time between the 2 surgeries was 23.7 months. Plain X-rays supported the diagnosis in 38.7% of cases, dynamic X-rays showed hypermobility in 50% of cases. The CT-scan demonstrated pseudarthrosis in 94,4% of cases. A MODIC 1 signal was observed in 87,2% of cases on MRI. SPECT-CT showed a tracer uptake in 70% of cases.

CONCLUSION

Reducing the time to reintervention is a key objective for improving the management and clinical outcomes of these patients. We suggest that MRI is an additional tool in combination with CT in the assessment of suspected mechanical pseudarthrosis, in order to optimize the diagnosis and shorten the time to revision surgery.

LEVEL OF EVIDENCE

IV.

The relationship between traction spurs, Modic change, vacuum phenomenon, and segmental instability of the lumbar spine

A thorough understanding of lumbar segmental motion is valuable to treat patients with degenerative lumbar disease, but kinematics associated with indicators of lumbar intervertebral instability [traction spur, Modic changes (MCs) and vacuum phenomenon (VP)] in the lumbar spine have not been well understood. The purpose of this study is to evaluate the relationships between traction spur, MCs and VP to radiographic measurements in the lumbar spine. A total of 525 lumbar discs from L1-2 to L5-S1 of 105 patients were evaluated. The sagittal translation (ST) and sagittal angulation were measured from the radiographs taken flexion–extension. The anterior disc height (ADH) was measured from the lateral radiographs, and ΔADH was measured as the difference from supine to sitting position. Logistic regression analyses were used to detect the association between the existence of traction spur, MCs and VP and related factors. Multivariate analysis showed that the traction spur was significantly related to translational motion (ST > 2 mm, OR 4.74) and the VP was significantly related to vertical motion (ΔADH > 3 mm, OR 1.94). These results suggest that the segments with traction spur and VP should be evaluated carefully because these may be a sign of lumbar intervertebral instability.

Modic Change: An Emerging Complication in the Aging Population

STUDY DESIGN

This was a literature review.

OBJECTIVE

The objective of this study was to review the pathogenesis, prevalence, clinical associations, diagnostic modalities, and treatment options for patients with lower back pain (LBP) associated with Modic change (MC).

SUMMARY OF BACKGROUND DATA

Vertebral body endplates are located between the intervertebral disk and adjacent vertebral body. Despite their crucial roles in nutrition and biomechanical stability, vertebral endplates are extremely susceptible to mechanical failure. Studies examining the events leading to disk degeneration have shown that failure often begins at the endplates. Endplate degeneration with subchondral bone marrow changes were originally noticed on magnetic resonance imaging. These magnetic resonance imaging signal changes were classified as MC.

METHODS

A literature review was conducted on the history, etiology, risk factors, diagnostic modalities, and treatment of LBP with MC.

RESULTS

Type 1 MC refers to the presence of increased vascularization and bone marrow edema within the vertebral body. Type 2 MC involves fatty marrow replacement within the vertebral body. Type 3 MC reflects subchondral bone sclerosis. Despite the original classification, research has supported the notion that MCs possess a transitional nature. Furthermore, type 1 MCs have been strongly associated with inflammation and severe LBP, while types 2 and 3 tend to be more stable and demonstrate less refractory pain. With a strong association to LBP, understanding the etiology of MC is crucial to optimal treatment planning. Various etiologic theories have been proposed including autoimmunity, mechanics, infection, and genetic factors.

CONCLUSIONS

With the aging nature of the population, MC has emerged as an extremely prevalent issue. Research into the pathogenesis of MC is important for planning preventative and therapeutic strategies. Such strategies may include rehabilitation, surgical fixation, stabilization, steroid or cement injection, or antibiotics. Improved diagnostic methods in clinical practice are thus critical to properly identify patients suffering from MC, plan early intervention, and hasten return to functioning.

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.

The Association of MRI Findings and Long-Term Disability in Patients With Chronic Low Back Pain

STUDY DESIGN

Longitudinal cohort study with 13-year follow-up.

OBJECTIVE

To assess whether long-term disability is associated with baseline degenerative magnetic resonance imaging (MRI) findings in patients with low back pain (LBP).

METHODS

In 2004-2005, patients aged 18 to 60 years with chronic LBP were enrolled in a randomized controlled trial and lumbar MRI was performed. Patients completed the Roland-Morris Disability Questionnaire (RMDQ) and the LBP Rating Scale, at baseline and 13 years after the MRI. Multivariate regression analysis was performed with 13-year RMDQ as the dependent variable and baseline disc degeneration (DD, Pfirrmann grade), Modic changes (MC), facet joint degeneration (FJD, Fujiwara grade) smoking status, body mass index, and self-reported weekly physical activity at leisure as independent variables.

RESULTS

Of 204 patients with baseline MRI, 170 (83%) were available for follow-up. Of these, 88 had Pfirrmann grade >III (52%), 67 had MC (39%) and 139 had Fujiwara grade >2 (82%) on at least 1 lumbar level. Only MC (β = -0.15, P = .031) and weekly physical activity at leisure (β = -0.51, P < .001) were significantly, negatively, associated with 13-year RMDQ-score (R² = 0.31).

CONCLUSION

DD and FJD were not associated with long-term disability. Baseline MC and weekly physical activity at leisure were statistically significantly associated with less long-term disability.

Influence of Modic Changes on Cage Subsidence and Intervertebral Fusion after Single-Level Anterior Cervical Corpectomy and Fusion

OBJECTIVES

This retrospective study aimed to determine the impact of Modic changes (MCs) on cage subsidence (CS) and intervertebral fusion after anterior cervical corpectomy and fusion (ACCF).

METHODS

This study enrolled 61 patients with MCs who underwent single-level ACCF between January 2010 and December 2015 at our institution. The control group included 63 age-matched patients without MCs treated during the same period. The results from clinical and radiological assessments were reviewed, and radiographic CS was defined by an intervertebral height at the final follow-up that was less than the postoperative intervertebral height.

RESULTS

No significant differences in gender, age, operative time, blood loss, or follow-up results were observed between the MCs and control groups. Significantly more patients experienced CS in the MCs group than in the control group (41.0% vs. 15.9%; p = 0.003). The frequencies of CS among patients with type I MCs (40.0%, 8/20) and type II MCs (41.5%, 17/41) were significantly higher than that in the control group (15.9%, 10/63; p < 0.05). Both groups showed significant improvements in clinical assessment scores after surgery and at final follow-up compared with preoperative values (p < 0.05).

CONCLUSION

In summary, all 61 patients with MCs who underwent ACCF achieved good fusion results. MCs in the surgical segment had no significant effect on intervertebral fusion, but both type 1 and type 2 MCs may increase the risk of CS.

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.

Modic Changes Are Not Associated With Long-term Pain and Disability: A Cohort Study With 13-year Follow-up

STUDY DESIGN

A comparative cohort study with 13-year follow-up.

OBJECTIVE

To assess whether Modic changes (MCs) are associated with long-term physical disability, back pain, and sick leave.

SUMMARY OF BACKGROUND DATA

Previous studies have shown a conflicting association of low back pain (LBP) with MCs and disc degeneration. The long-term prognosis of patients with MCs is unclear.

METHODS

In 2004 to 2005, patients aged 18 to 60 with daily LBP were enrolled in an randomized controlled trial study and lumbar magnetic resonance imaging (MRI) was performed. Patients completed numeric rating scales (0-10) for LBP and leg pain, Roland-Morris Disability Questionnaire (RMDQ), LBP Rating Scale for activity limitations (RS, 0-30), inflammatory pain pattern and sick leave days due to LBP at baseline and 13 years after the MRI. Patients were stratified based on the presence (+MC) or absence (-MC) of MCs on the MRI.

RESULTS

Of 204 cases with baseline MRI, 170 (83%) were available for follow-up; 67 (39%) with MCs and 103 (61%) without MCs. Demographics, smoking status, BMI, use of antibiotics, LBP, leg pain, and inflammatory pain pattern scores at baseline and at 13-year follow-up were similar between the two groups. Also, baseline RMDQ was similar between the +MC and -MC groups. At 13 years, the RMDQ score was statistically significant better in the +MC group (7.4) compared with the -MC group (9.6, P = 0.024). Sick leave days due to LBP were similar at baseline but less in the +MC group (9.0) compared with the -MC group (22.9 d, P = 0.003) at 13 years.

CONCLUSION

MCs were not found to be negatively associated with long-term pain, disability, or sick leave. Rather, the study found that LBP patients with MCs had significantly less disability and sick-leave at long-term follow-up. We encourage further studies to elucidate these findings.

LEVEL OF EVIDENCE

2.