Frequency of Vertebral Endplate Modic Changes in Patients with Unstable Lumbar Spine and Its Effect on Surgical Outcome

Prediction of fusion cage subsidence after transforaminal lumbar interbody fusion based on MRI endplate bone quality

Background

Transforaminal lumbar interbody fusion (TLIF) is a significant surgical method for treating degenerative lumbar diseases. Cage subsidence is one of the common postoperative complications of TLIF surgery. Current research lacks imaging prediction methods for cage subsidence in TLIF surgery. Endplate bone quality (EBQ) based on magnetic resonance imaging (MRI) is currently regarded as a potentially effective method for predicting cage subsidence. This study aimed to investigate the correlation between EBQ and cage subsidence.

Methods

A retrospective analysis was conducted on the data of 102 patients who underwent TLIF surgery between October 2022 and October 2023. Patients' vertebral bone quality (VBQ) and EBQ scores were measured using MRI. Patients were divided into a subsidence group and a non-subsidence group based on whether the postoperative fusion device subsided. The preoperative VBQ, EBQ, bone mineral density (BMD) values, preoperative and postoperative 3-month and final follow-up Visual Analogue Scale (VAS) scores, Oswestry Disability Index (ODI) scores, disc height (DH), lumbar lordosis (LL) angle, and segmental lordosis (SL) angle were compared between the two groups. Logistic regression curves were used to study the correlations.

Results

Among 102 patients, 23 patients (22.5%) experienced cage subsidence. The DH, LL, and SL in both groups increased postoperatively, at 3 months postoperatively, and at the final follow-up when compared to preoperative values (P<0.05). The EBQ score was 2.63±0.40 for the non-subsidence group and 3.40±0.49 for the subsidence group, with a significant difference between the two groups. The EBQ score is a predictive factor for cage subsidence after TLIF. A higher score significantly increases the risk of cage subsidence [odds ratio (OR) =74.95; 95% confidence interval (CI): 11.8-472; P<0.001]. On the receiver operating characteristic (ROC) curve, the area under the curve (AUC) for the EBQ score was 0.863 (95% CI: 0.815-0.924), and the optimal threshold for the EBQ score was 3.125 (sensitivity: 84.3%; specificity: 72.2%).

Conclusions

The EBQ score can predict the occurrence of cage subsidence in patients undergoing TLIF surgery. Patients with higher EBQ scores have a higher incidence of cage subsidence.

The effect of Modic changes on the fusion rates of posterior interbody fusion surgery

BACKGROUND

Modic changes have been correlated to low back pain, spinal instability. The objective of this study was to evaluate the effect of Modic changes on the fusion rates of instrumented posterior interbody fusion surgery (PLIF).

METHODS

The study included patients who underwent PLIF surgery between 2015-2019.The patients were separated into four groups according to Modic changes detected in the preoperative MRI. Fusion, subsidence were evaluated with postoperative CT and X-ray. Body mass index (BMI) and bone mineral density (BMD) of the patients were also evaluated.

RESULTS

The study included 137 operated discs of 86 patients. There was no statistical difference between groups regarding age, gender, follow-up period, BMI, and BMD. There were 70 levels with no Modic changes (M0), 26 levels with Modic type 1 (M1), 21 levels with Modic type 2 (M2), and 16 with Modic type 3 (MC3) change. The rate of successful fusion was 92.9% in M0, 92.3% in M1, 93% in M2, and 93.7% in M3. The rate of high-grade subsidence was 28.5% in M0, 26.8% in M1, 27.5% in M2, and 24.9% in M3. There was no statistically difference between the patients regarding subsidence grade or fusion rate.

CONCLUSIONS

Modic changes were not observed to be directly correlated to the radiological outcomes of instrumented posterior interbody fusion. The fusion rate demonstrated homogenous distribution between the Modic groups and the subsidence rate was slightly higher in MC1 and MC2 than in MC3 and MC0.

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.

The influence of endplate (Modic) changes on clinical outcomes in lumbar spinal stenosis surgery: a Swiss prospective multicenter cohort study

PURPOSE

To investigate if the presence or absence of preoperative endplate Modic changes (MC) is predictive for clinical outcomes in degenerative lumbar spinal stenosis (DLSS) patients undergoing decompression-alone or decompression with instrumented fusion surgery.

METHODS

Two hundred five patients were included and categorized into four groups; 102 patients into the decompression-alone group with MCs, 41 patients into the fusion group with MCs, 46 patients into the decompression-alone group without MCs, and 16 patients into the fusion group without MCs. Clinical outcome was quantified with changes in spinal stenosis measure (SSM) symptoms, SSM function, NRS pain, and EQ-5D-3L sum score over time (measured at baseline, 12-, 24-, and 36-month follow-up) and minimal clinically important difference (MCID) in SSM symptoms, SSM function, and NRS pain from baseline to 36-month follow-up. To investigate if possible effects of MCs had been modified or hidden by confounding variables, we used the group LASSO method to search for good prognostic models.

RESULTS

There were no obvious differences in any of the clinical outcome measures between groups at baseline. At 12 months, most patients have improved in all outcomes and maintained improved conditions over time (no significant group differences). Between 70 and 90 percent of the patients maintained a clinically important improvement up to 36 months.

CONCLUSIONS

Endplate MCs have no significant influence on clinical outcome parameters in patients with lumbar spinal stenosis compared to patients without MCs, independent of the chosen surgical strategy. All patients benefitted from surgical therapy up to 36-month follow-up. These slides can be retrieved under Electronic Supplementary Material.

Imaging in Spine Surgery: Current Concepts and Future Directions

OBJECTIVE

To review and highlight the historical and recent advances of imaging in spine surgery and to discuss current applications and future directions.

METHODS

A PubMed review of the current literature was performed on all relevant articles that examined historical and recent imaging techniques used in spine surgery. Studies were examined for their thoroughness in description of various modalities and applications in current and future management.

RESULTS

We reviewed 97 articles that discussed past, present, and future applications for imaging in spine surgery. Although most historical approaches relied heavily upon basic radiography, more recent advances have begun to expand upon advanced modalities, including the integration of more sophisticated equipment and artificial intelligence.

CONCLUSIONS

Since the days of conventional radiography, various modalities have emerged and become integral components of the spinal surgeon's diagnostic armamentarium. As such, it behooves the practitioner to remain informed on the current trends and potential developments in spinal imaging, as rapid adoption and interpretation of new techniques may make significant differences in patient management and outcomes. Future directions will likely become increasingly sophisticated as the implementation of machine learning, and artificial intelligence has become more commonplace in clinical practice.

Effect of Preoperative Modic Change in the Outcome of Patients with Low Back Pain Following Posterior Spinal Fusion or Laminectomy

Background

Modic changes (MC), visible on magnetic resonance imaging (MRI) are associated with chronic low back pain (LBP). It is reported that different MC types could affect the surgical outcome in patients with LBP.

Objective

In this study, we evaluated the effect of MC Type I and II on patients with LBP and degenerative disc disease following posterior spinal fusion (PSF) or laminectomy.

Materials and Methods

We evaluated the outcome of 162 patients with LBP and MC Type I and II who underwent laminectomy (n = 72) or PSF (n = 90). Preoperative MRI was used to define MC types. Visual analog scale (VAS) was used to evaluate the pain intensity before and 3 months after surgery.

Results

Patients had MC Type I in 46.3% and Type II in 53.7%. Pain VAS significantly decreased following surgery (7.93 ± 1.27-5.98 ± 1.57, P < 0.001). There was no difference between MC Type I and II in pain VAS before (P = 0.51) and after treatment (P = 0.51). Among MC Type I, PSF compared to laminectomy had significantly more improvement in pain VAS (P = 0.01), but the changes in modic Type II were similar between groups (P = 0.89).

Conclusion

Surgical treatment in patients with LBP with MC accompanies with significant improvement in pain. PSF seems better treatment in patients with MC Type I.

Analysis of Correlation Between Vertebral Endplate Change and Lumbar Disc Degeneration

Background

To evaluate the correlation between vertebral endplate change and the level of lumbar disc degeneration via magnetic resonance imaging (MRI).

Material/Methods

A total of 345 patients who were recruited from our hospital from May 2012 to May 2016 were evaluated for the presence of intervertebral disc degeneration or herniation. The degree of degeneration was assessed according to Pfirrmann grade. Vertebral endplate change was evaluated based on the endplate concave angle (ECA), and Modic change on sagittal MRI. The correlation between ECA and lumbar disc degeneration or Modic change and lumbar disc degeneration was analyzed.

Results

The results showed that there was no statistically significant difference in comparison of the ECAs in adjacent L3–5 vertebra between males and females. With the aggravation in degenerative changes of L3–5 discs, the ECAs of adjacent L3 superior endplate, L4 inferior and superior endplates and L5 inferior endplate were gradually enlarged, indicating the positive correlation between the lumbar disc degeneration and ECAs. The rate of Modic change in females was higher than that in males without a statistically significant difference. Area of Modic change was positively correlated with the degree of lumbar disc degeneration. Additionally, we also identified the positive correlation between the rate of Modic change and the degree of lumbar disc degeneration.

Conclusions

Endplate angle and lumbar disc degeneration are positively correlated. The endplates and endplate signal changes can reflect the degree of disc degeneration and Modic changes can reflect the rate of clinical lumbar disc degeneration degree.

[Expression and significance of hypoxia-inducible factor 1α in endplate chondrocytes of rats]

Objective

To explore the expression and significance of hypoxia-inducible factor 1α (HIF-1α) in endplate chondrocytes, and to study the relations between HIF-1α expression and endplate chondrocytes apoptosis.

Methods

Eight Sprague Dawley rats were selected to obtain the L _1-5 intervertebral disc endplate; the endplate chondrocytes were isolated by enzyme digestion method, and the endplate chondrocytes at passage 3 were cultured under 20% O ₂ condition (group A), and under 0.5% O ₂ condition (group B). Cell morphology was observed by inverted phase contrast microscope and cell apoptosis was detected using flow cytometry after cultured for 24 hours; the mRNA expression of HIF-1α was detected by real-time fluorescent quantitative PCR, the protein expressions of HIF-1α, Bax, and Bcl-2 by Western blot. Gene clone technology to design and synthesize two siRNAs based on the sequence of HIF-1α mRNA. HIF-1α specific RNAi sequence compound was constructed and transfected into cells. The transfected endplate chondrocytes at passage 3 were cultured under 0.5% O ₂ condition in group C and group D (HIF-1α gene was silenced). After cultured for 24 hours, cells were observed via immunofluorescence staining of HIF-1α, and cell apoptosis was detected using flow cytometry. Meanwhile, the mRNA expressions of HIF-1α, collagen type II (COL II), Aggrecan, and SOX9 were detected by real-time fluorescent quantitative PCR, and the protein expressions of HIF-1α, Bax, and Bcl-2 by Western blot.

Results

At 24 hours after culture, small amount of vacuoles necrotic cells could be observed in group A and group B; there was no significant difference in apoptosis rate between groups A and B ( t=1.026, P=0.471), and HIF-1α mRNA and protein expressions in group B were significantly higher than those in group A ( t=22.672, P=0.015; t=18.396, P=0.013), but, there was no significant difference in protein expressions of Bax and Bcl-2 between groups A and B ( t=0.594, P=0.781; t=1.251, P=0.342). The number of vacuolar necrosis cells in group D was significantly higher than that in group C, and HIF-1α positive cells were observed in group D. The apoptosis rate of group D was significantly higher than that of group C ( t=27.143, P=0.002). The mRNA expressions of HIF-1α, COL II, Aggrecan, and SOX9 in group D were significantly lower than those in group C ( t=21.097, P=0.015; t=34.829, P=0.002; t=18.673, P=0.022; t=31.949, P=0.007). The protein expressions of HIF-1α and Bcl-2 in group D were significantly lower than those in group C ( t=37.648, P=0.006; t=16.729, P=0.036), but the protein expression of Bax in group D was significantly higher than that in group C ( t=25.583, P=0.011).

Conclusion

HIF-1α mRNA expression is up-regulated under hypoxia condition, which will increase the hypoxia tolerance of endplate chondrocytes. Cell apoptosis is suppressed by the activation of HIF-1α in endplate chondrocytes under hypoxia condition.