Absence of Bone Marrow Edema on Early Postoperative MRI Predicts Fusion Outcome After Single-Level Lumbar Interbody Fusion

Absence of Bone Marrow Edema on Early Postoperative MRI Predicts Fusion Outcome After Single-Level Lumbar Interbody Fusion | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Absence of Bone Marrow Edema on Early Postoperative MRI Predicts Fusion Outcome After Single-Level Lumbar Interbody Fusion Yukitoshi Shimamura, Masahiro Kanayama, Fumihiro Oha, Michihaya Kono, and 7 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8644981/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 8 You are reading this latest preprint version Abstract Purpose: This study aimed to investigate whether bone marrow edema observed on MRI at three-postoperative week can predict fusion status in a single-level lumbar interbody fusion. Methods: This retrospective study included 152 patients who had undergone a single-level lumbar interbody fusion with a minimum of one-year follow-up. All patients underwent MRI at three weeks after surgery and CT scans at 3, 6, and 12 postoperative months. CT scans were used to evaluate fusion status, presence of vertebral endplate cyst (VEC), trabecular bone remodeling (TBR), and cage subsidence. Patients were divided into two groups based on MRI findings: those with bone marrow edema (edema group) and those without (non-edema group). Bone marrow edema was defined as a low-intensity area within the adjacent vertebral bodies on T1-weighted images. Clinical and radiographic outcomes were compared between groups. Results: Of 152 patients, 117 were assigned to the edema group and 35 to the non-edema group. The non-edema group demonstrated significantly higher fusion rates at 3, 6, and 12 months postoperatively. Additionally, the non-edema group showed a significantly lower incidence of VEC and a higher frequency of TBR. Cage subsidence was not observed in any patients in the non-edema group, whereas 22.2% of patients in the edema group exhibited cage subsidence at 12 months. Conclusion: Absence of bone marrow edema on MRI assessment at three postoperative week was associated with significantly higher fusion rates. These results suggest that absence of early bone marrow edema may serve as a predictor of successful fusion after single-level lumbar interbody fusion. bone marrow edema fusion status early postoperative period lumbar interbody fusion vertebral endplate cyst trabecular bone remodeling Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Introduction Lumbar interbody fusion widely performed to address degenerative lumbar spine conditions [ 1 , 2 ], especially in aging population. As life expectancy increases globally, the prevalence of lumbar pathologies has risen, leading to greater demand for fusion surgeries [ 1 , 3 – 5 ]. Although these procedures often provide clinical benefits such as pain relief and neurological improvement, complications remain. Among them, pseudoarthrosis—a failure of osseous union—continues to pose significant clinical challenges, frequently resulting in implant instability, persistent symptoms, and need for revision surgery [ 6 – 8 ]. Numerous studies have examined risk factors for pseudoarthrosis, including age, smoking status, low bone mineral density (BMD), and multilevel fusions [ 9 – 14 ], yet accurate prediction of fusion success remain difficult. Postoperative imaging, particularly computed tomography (CT), has been used to assess signs such as vertebral endplate cyst (VEC) [ 15 ], trabecular bone remodeling [ 16 , 17 ], and cage subsidence, which may reflect fusion progression or failure. However, these markers typically emerge several months after surgery, limiting their value for early prediction. In contrast, magnetic resonance imaging (MRI), though commonly used for preoperative evaluation, has been investigated for its utility in predicting postoperative fusion. Clinical observations have revealed that some patients exhibit bone marrow edema near the fused segment during early postoperative MRI, while others do not. 18 Bone marrow edema is generally considered to reflect inflammation, microdamage in the vertebral body [ 18 – 23 ], but its relationship with bone fusion is still unclear; it has yet to be determined whether bone marrow edema represents favorable biological remodeling promoting osseous integration, or instead indicates disruptive mechanical instability that impairs bone healing. Prior reports lacked systematic evaluation of the prognostic implications over time, and thus, further investigation is warranted to clarify whether the presence or absence of bone marrow edema serves as a meaningful predictor of fusion outcomes. This study was designed to test the hypothesis that early postoperative bone marrow edema, identified by MRI, is predictive of subsequent fusion status evaluated by CT. By determining the clinical relevance of this early imaging feature, the study aims to establish a new prognostic tool that can guide postoperative management more effectively. Identification of bone marrow edema as an early marker may allow for timely clinical interventions such as adjusting brace protocols, optimizing imaging surveillance, or initiating osteoanabolic therapy. Expanding the prognostic role of MRI could improve outcomes in lumbar interbody fusion by enabling tailored and anticipatory postoperative care. Materials and Methods Study Design and Ethical Approval This retrospective observational study was conducted at our Spine Center and was approved by the clinical ethics committee (Approval No: 2025-04). All procedures adhered to the principles of the Declaration of Helsinki and relevant guidelines. Informed consent was waived due to the study’s retrospective nature and anonymous of patient data. Patient Selection Medical records and imaging data of patients who underwent one-segment lumbar interbody fusion at a single institution between April 2020 and May 2023. A total of 152 patients met the following inclusion criteria: 1) neurological symptoms caused by focal stenosis, 2) surgical procedure: posterior lumbar interbody fusion (PLIF) or transforaminal lumbar interbody fusion (TLIF), 3) availability of one-year follow-up, 4) MRI was performed three weeks after surgery, (5) CT imaging scan obtained at 3, 6 and 12 postoperative months. Exclusion criteria were as follows; 1) follow-up period less than one year, 2) History of prior spinal fusion surgery, 3) surgery performed for traumas or spinal tumors, (4) preoperative Modic change in the fused segment, (5) age under 18 years. Demographic valuables collected included age, sex, body mass index (BMI), smoking status, the presence of diabetes mellitus (DM), lumbar and femoral bone BMD (T-score), and fusion level. Surgical procedure A posterior midline approach was used in all cases. Following exposure of the relevant vertebrae, pedicle screw and rods were placed before decompression. After distraction and temporary fixation, the caudal half of lamina and the inferior articular processes of the cranial vertebra were removed, and ligamentum flavum was excised. The intervertebral disc and cartilaginous endplates were cleared, and autologous bone graft was harvested from the resected lamina and processes using a bone mill. Artificial bone was added when necessary. No iliac crest harvesting was performed. Interbody cages were inserted and final fixation was achieved by compressing the pedicle screws. A cross-link was installed in all cases unless anatomically restricted. Postoperative ambulation with a lumbar corset (MAXBELTme2, SIGMAX, Japan) began on the first day after surgery. Radiographic parameters CT Assessment CT scan was performed at 3, 6, and 12 postoperative months (Aquilion 64, Canon, Japan / Aquilion ONE, Canon, Japan). The following parameters were recorded: a) fusion status : defined as continuous bony bridging across the intervertebral space on both coronal or sagittal images, b) cage subsidence : defined as ≥ 2 mm downward migration of the interbody cage into the vertebral body, c) VEC : cystic lesions observed at the vertebral endplates of the fused segment. VEC is used as the predictor for non-union (Fig. 1 ) [ 15 ]. d) TBR : radiographic changes in trabecular patterns of adjacent vertebral bodies, indicating remodeling activity. TBR is known as the predictive findings of successful interbody fusion (Fig. 2 ) [ 16 ]. For all CT findings, evaluation was performed by two spine surgeons (Y.S. and K.S.). In cases of disagreement, a final decision was reached by consensus. MRI finding All patients underwent MRI examination three weeks after surgery using the T system (Signa HDxt ® ; GE Medical Systems Information Technologies Inc., USA). Bone marrow edema was defined as a low-intensity area in the vertebral body on T1-weighted images (TR 500 ms, TE 10 ms; slice thickness 5mm; gap 1 mm; number of excitations 2; echo train 3) (Fig. 3 ). Evaluation was independently performed by two spine surgeons. To assess intra-observer reliability, the same examiner (Y.S.) performed measurements twice with an interval of more than one week. Inter-observer reliability was assessed using independent measurement performed by two examiners (Y.S. and K.S.). In cases of disagreement, a final decision was reached by consensus. Intra-observer reliability of bone marrow edema was substantial; kappa coefficient was 0.77 (0.65–0.89). Inter-observer reliability was moderate; kappa coefficient was 0.57 (0.41–0.74). Additional surgery We reviewed the type and cause of additional surgeries performed within one year after the initial surgery based on medical records. Statistical analysis The patients were divided into edema group (with bone marrow edema) and non-edema group (without edema). We compared measured valuables between the two groups. As a sub-analysis, fusion status, cage subsidence, VEC and TBR were analyzed according to the edema patterns reported by Hasegawa et al. 18 Pearson chi-square analysis was performed to assess the statistical significance of categorical data, including sex, smoking status, DM, fusion status, the occurrence of VEC, TBR, and cage subsidence. Continuous data were compared between the two groups using unpaired t-test. Inter- and intra-observer reliability were assessed using Cohen’s kappa (κ) coefficient. Cohen’s κ coefficient was interpreted as follows: < 0.00: poor, 0.00-0.20: Slight, 0.21–0.40: Fair, 0.41–0.60: Moderate, 0.61–0.80: Substantial, 0.81-1.00: Almost Perfect. All analyses were performed using Bellcurve for Excel ver. 4.08 (Social Survey Research Information Co., Ltd. Japan), and a p-value < 0.05 was considered significant. Missing data The following items had missing data: lumbar BMD, 3.9% (6/152); femoral neck BMD, 4.6% (7/152). In group comparisons, missing data were treated as blanks. Results Patients Demographics Patients included in this study were 74 men and 78 women with a mean age of 68.8 years (30–88 years) at the initial surgery. Smoking status was classified as follows: non-smoker, former smoker (who had quit smoking at least 6 months before surgery), and current smoker. There were 82 non-smokers, 28 former smokers, 34 current smokers. The rate of DM was 22.2% (34 /153 patients). Mean lumbar BMD was 0.1 (-3.2–5) and mean femoral neck BMD was − 1.2 (-3.9–2.1). The fusion segments were distributed as follows: L1/2 in 4 patients, L2/3 in 3, L3/4 in 25, L4/5 in 81, L5/6 in 1, L5/S1 in 38 (Table 1 ). Table 1 Patient characteristics (N = 152) Age (years) 68.8 ± 11.5 Sex (men / women) 74 / 78 BMI (kg/m 2 ) 25 ± 3.9 Smoking status, n (%) Non smoker 82 (53.9%) Former smoker 28 (18.4%) Current smoker 34 (22.4%) Unclear 8 (5.3%) The history of DM 34 (22.4%) BMD (T-score) Lumbar 0.1 ± 1.7 Femoral neck -1.2 ± 1.1 Fusion segment L1/2 4 (2.6%) L2/3 3 (2%) L3/4 25 (16.4%) L4/5 81 (53.3%) L5/6 1 (0.7%) L5/S1 38 (25%) Data are shown as means ± standard deviations or numbers (percentages). BMI: body mass index, DM: diabetes mellitus, BMD: bone mineral density A total of 152 patients were included in the final analysis. Among them, 117 patients exhibited bone marrow edema on early postoperative MRI at three weeks and were assigned to the edema group, while 35 patients without edema comprised the non-edema group. The non-edema group accounted for 23% of the cohort. No significant differences were observed between groups in terms of age, sex distribution, BMI, smoking status, diabetes history, lumbar BMD, and femoral neck BMD (Table 2 ). Table 2 Patient characteristics of edema group and non-edema group edema group non-edema group p -value Patients 117 35 Age (years) 68.7 ± 11.1 69.2 ± 12.7 0.797 Sex men / women 59/58 15/20 0.432 BMI (kg/m 2 ) 24.9 ± 3.6 25.2 ± 4.8 0.758 Smoking status 0.127 Non smoker 51.3% (60) 62.9% (22) Former smoker 16.2% (19) 25.7% (9) Current smoker 25.6% (30) 11.4% (4) The history of DM 20.5% (24) 28.6% (10) 0.316 BMD (T-score) Lumbar 0.1 ± 1.5 0.3 ± 2.2 0.429 Femoral neck -1.2 ± 1 -1.2 ± 1.2 0.885 Data are shown as means ± standard deviations or percentages (numbers). BMI: body mass index, DM: diabetes mellitus, BMD: bone mineral density Bone Fusion Status CT-based evaluation demonstrated significantly higher fusion rates in the non-edema group across all time points. At 3 months postoperatively, fusion was achieved in 85.7% of non-edema patients versus 31.6% of edema patients (p < 0.001). At 6 months, rates were 91.2% versus 47.9%, respectively (p < 0.001), and 12 months, 91.2% in the non-edema group versus 72.6% in the non-edema group (p = 0.024), confirming a consistent trend favoring patients without postoperative bone marrow edema (Fig. 4 ). Cage subsidence Cage subsidence occurred exclusively in the edema group. At 3months, 20.5% of edema patients experienced subsidence compared to 0% in the non-edema group (p = 0.004). The difference remained significant at 6 months (21.4% vs. 0%, p = 0.003) and 12 months (22.2% vs. 0%, p = 0.002), indicating a strong association between bone marrow edema and postoperative mechanical instability (Table 3 ). Table 3 CT findings of edema group and non-edema group edema group non-edema group p -value The occurrence of VEC 3 months 28.2% (33) 5.7% (2) 0.006 6 months 29.9% (35) 11.4% (4) 0.026 12 months 26.5% (31) 8.6% (3) 0.024 The occurrence of TBR 3 months 37.6% (44) 54.2% (19) 0.079 6 months 47.9% (56) 60% (21) 0.224 12 months 39.3% (46) 62.9% (22) 0.017 Cage subsidence 3 months 20.5% (24) 0% (0) 0.004 6 months 21.4% (25) 0% (0) 0.003 12 months 22.2% (26) 0% (0) 0.002 Data are shown as percentages (numbers). VEC: vertebral endplate cyst, TBR: trabecular bone remodeling VEC occurrence The incidence of VEC was significantly lower in the non-edema group. At 3 months, VEC appeared in 5.7% of non-edema patients compared to 28.2% in the edema group (p = 0.006). This pattern persisted at 6 months (11.4% vs. 29.9%, p = 0.026), and at 12 months (8.6% vs. 26.5%, p = 0.024) (Table 3 ). TBR Although not statistically significant at early points (at 3 months: 54.2% vs. 37.6%, p = 0.079; 6 months 60% vs. 47.6%, p = 0.224), TBR tended to be more frequent in the non-edema group and became significant at 12 months (62.9% vs. 39.3%, p = 0.017) (Table 3 ). Comparison among edema patterns Hasegawa et al. reported that bone marrow edema were divided into three patterns: 1) anterior corner pattern, 2) around-the-cage pattern, 3) diffuse pattern (Fig. 5 ) [ 18 ]. In present study, 42 patients (27.6%) were classified into anterior corner pattern, 66 (43.4%) into around-the-cage pattern, and nine (5.9%) into diffuse pattern. No statistically significant differences were observed in fusion status among three groups, but diffuse pattern showed following tendencies: occurrence of early postoperative cage subsidence and VEC, and lower incidence of TBR compared to other patterns (Table 4 ). Table 4 Comparison among three patterns Anterior corner Around-the-cage diffuse p -value Patients 42 66 9 Successful fusion 3 months 21.4% (9) 39.4% (26) 33.3% (3) 0.151 6 months 48.8% (20) 30.3% (20) 44.4% (4) 0.146 12 months 65.9% (27) 66.7% (44) 66.7% (6) 0.996 The occurrence of VEC 3 months 19% (8) 24.2% (16) 44.4% (4) 0.268 6 months 22% (9) 25.8% (17) 44.4% (4) 0.378 12 months 19.5% (8) 18.2% (12) 22.2% (2) 0.953 The occurrence of TBR 3 months 38.1% (16) 37.9% (25) 11.1% (1) 0.272 6 months 46.3% (19) 37.9% (25) 11.1% (1) 0.141 12 months 41.5% (17) 37.9% (25) 11.1% (1) 0.228 Cage subsidence 3 months 21.4% (9) 13.6% (9) 44.4% (4) 0.074 6 months 29.3% (12) 16.7% (11) 44.4% (4) 0.096 12 months 31.7% (13) 18.2% (12) 44.4% (4) 0.109 Data are shown as percentages (numbers). VEC: vertebral endplate cyst, TBR: trabecular bone remodeling Additional surgery Additional surgery was performed only one patient in the edema group. Extension of spinal segmental fusion surgery was undergone for pedicle fracture and instrumentation failure between 3 and 6 months postoperatively. Discussion This study demonstrated that absence of bone marrow edema on early postoperative MRI was significantly associated with successful interbody fusion following single-level lumbar interbody fusion surgery. Patients without edema showed higher rates of bony union over time and exhibited favorable radiographic characteristics, including reduced incidence of VEC, increased TBR, and notably, no cage subsidence. These findings support the potential utility of early MRI in postoperative evaluation and highlight the prognostic relevance of bone marrow edema in spinal fusion outcomes. Our findings raise the possibility that early postoperative changes visible on imaging offer a more accurate reflection of the biomechanical and biological conditions relevant to fusion than clinical and demographic factors present before surgery. Various patient-related risk factors for pseudoarthrosis—such as age, smoking, and low BMD—have been widely reported [ 9 – 14 , 24 ], but the present study did not identify significant differences in demographic or metabolic variables between the edema and the non-edema groups. Previous investigations have focused primarily on CT-based indicators, such as VEC and TBR, evaluated at later postoperative stage. Fujibayashi, et al. reported that VEC formation on CT at 3 months postoperatively predicted subsequent union status and clarified that the case who has VEC formation on early postoperative CT developed into nonunion [ 15 ]. Segi, et al. reported the relationship between successful interbody fusion and the occurrence of TBR on CT at 3 months postoperatively, and patients with early TBR did not experience pedicle screw cutout nor pseudarthrosis and had significantly fewer VECs than those without early TBR [ 16 ]. The study concluded that TBR may be a new radiological marker of initial fixation after PLIF. Both of these studies suggest that the possibility of pseudoarthrosis can be predicted at an early postoperative time point, specifically at three months. It is preferable to predict pseudoarthrosis after lumbar interbody fusion surgery as early as possible, as it allows for timely interventions such as extending the duration of brace immobilization, more frequent follow-up evaluations, and the administration of osteoanabolic agents such as parathyroid hormone when appropriate. Although other studies have recommended early postoperative CT for assessment, no reports to date have discussed the potential of early postoperative MRI for predicting bone fusion. The present study demonstrated that bone marrow edema on MRI could predict fusion status at 3 weeks postoperatively. In addition, bone marrow edema was also related to the occurrence of VEC and TBR. From the result of present study, bone marrow edema might represent an imaging finding capable of predicting future successful interbody fusion at an earlier postoperative stage. The present study demonstrated that absence of bone marrow edema on early postoperative MRI could predict successful interbody fusion and the inhibited cage subsidence. Recently, MRI has been increasingly used for the preoperative evaluation in spinal instrumentation surgeries; the endplate bone quality (EBQ) score is an MRI-based metric that quantifies signal intensity on T1-weighted images at the vertebral endplates, reflecting structural and compositional changes such as fatty infiltration, sclerosis, or inflammation [ 25 , 26 ]. Chen, et al. investigated whether EBQ score is related to cage subsidence or not; they reported risk of cage subsidence increased significantly with higher EBQ scores and higher EBQ score was an independent factor in predicting subsidence after TLIF [ 25 ]. Ai, et al. investigated vertebral bone quality (VBQ) score and EBQ score affect the occurrence of cage subsidence after one-segment lumbar interbody fusion [ 26 ]. Concluding that higher scores in both parameters were associated with increased risk. But few studies evaluated the association between MRI findings and bone union. Hu, et al. reported that a higher VBQ score was an independent risk factor for pedicle screw loosening following instrumented TLIF [ 27 ]. The results of present study suggested that MRI might be useful for both preoperative and postoperative evaluation. Bone marrow edema may represent a critical intermediary in the cascade leading to impaired bone fusion. Bone marrow edema is reported to be a consequence of local inflammatory reaction or microfractures with resultant edema or hemorrhage [ 19 – 23 ]. Based on these findings, our hypothesis regarding the relationship between bone marrow edema and impaired bone fusion is as follows; interoperative endplate manipulation leads to microdamage or microfracture of vertebral bone or vertebral endplate [ 28 , 29 ]. In addition, since cage insertion slightly elevates the intervertebral height, mechanical stress is exerted especially on the vertebral endplates around the cage. This damage and stress of vertebral body and endplate may occur inflammatory changes. These inflammatory changes could lead to vertebral endplate cyst formation, hinder bone remodeling, and ultimately impede bone fusion. As a result, slight intervertebral instability may occur, potentially leading to the development of pseudarthrosis. In the present study, among the three edema patterns, the diffuse pattern tended to show a higher incidence of early cage subsidence and VEC, as well as a lower incidence of TBR. These tendencies suggest that attention should be paid to the occurrence of early cage subsidence and VEC in diffuse pattern. However, as only nine cases of diffuse pattern were included in present study, further investigations with a larger sample size are needed. The present study has several limitations. The single-center design ensured surgical standardization but may limit generalizability. MRI was performed only once at three weeks; serial imaging might offer a more dynamic understanding of edema evolution and its relationship with fusion. Additionally, despite adequate intra- and inter-observer reliability, the subjective nature of edema interpretation warrants standardization of evaluation criteria. Finally, these findings are specific to single-level fusion procedures, and application to multi-level surgeries requires further investigation. Conclusion In summary, this study underscores the importance of early bone marrow edema as a radiographic finding and proposes its absence as a potential predictor of successful lumbar interbody fusion. Incorporating early postoperative MRI into routine assessment may provide a more refined and temporally sensitive framework for evaluating fusion trajectory and guiding postoperative management. Declarations Funding The authors declare that no funds, grants, or other support were received during the preparation of this manuscript. No funding was obtained for this study. Competing Interests The authors have no relevant financial or non-financial interests to disclose. Author contributions All authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Y.S. The first draft of the manuscript was written by Y.S. and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript. Consent to participate The requirement for informed consent was waived because of the retrospective nature of the study. Consent to publish This study doesn’t contain any images that could identify individuals. References Reisener MJ, Pumberger M, Shue J et al (2020) Trends of lumbar spinal fusion-a literature review. J Spine Surg 6(4):752–761. 10.21037/jss-20-492 Abdu WA, Sacks OA, Tosteson ANA et al (2018) Long-Term Results of Surgery Compared With Nonoperative Treatment for Lumbar Degenerative Spondylolisthesis in the Spine Patient Outcomes Research Trial (SPORT). Spine(Phila Pa 1976) 43(23):1619–1630. 10.1097/BRS.0000000000002682 Rajaee SS, Bae HW, Kanim LEA et al (2012) Spinal Fusion in the United States. Spine(Phila Pa 1976) 37:67–76. 10.1302/0301-620X.96B6 . Analysis of Trends From 1998 to 2008 Martin BI, Mirza SK, Spina N et al (2018) Trends in Lumbar Fusion Procedure Rates and Associated Hospital Costs for Degenerative Spinal Diseases in the United States, 2004 to 2015. Spine(Phila Pa 1976) 44(5):369–376 Imajo Y, Taguchi T, Yone K et al (2015) Japanese 2011 nationwide survey on complications from spine surgery. J Orthop Sci 20:38–54. 10.1007/s00776-014-0656-6 Makino T, Kaito T, Fujiwara H et al (2014) Does fusion status after posterior interbody fusion affect patient-based QOL outcomes? An evaluation performed using a patient-based outcome measure. J Orthop Sci 19:707–712. 10.1007/s00776-014-0591-6 Tsutsumimoto T, Shimogata M, Yoshimura Y et al (2008) Union versus nonunion after posterolateral lumbar fusion: a comparison of long-term surgical outcomes in patients with degenerative lumbar spondylosis. Eur Spine J 17:1107–1112. 10.1007/s00586-008-0695-9 Chun DS, Baker KC, Hsu WK (2015) Lumbar pseudarthrosis: a review of current diagnosis and treatment. Nuerosurg Focus 39(4):E10. 10.3171/2015.7.FOCUS15292 Phan K, Fedhil M, Chang N et al (2018) Effect of Smoking Status on Successful Arthrodesis, Clinical Outcome, and Complications After Anterior Lumbar Interbody Fusion (ALIF). World Neurosurg 110:e998–e1003 Konomi T, Yasuda A, Fumiyoshi K et al (2020) Incidences andRisk Factors for Postoperative Non-Union after Posterior Lumbar Interbody Fusion with Closed-Box Titanium Spacers. Asian Spine J 14(1):106–112 Cho JH, Hwang CJ, Kim H et al (2018) Effect of osteoporosis on the clinical and radiographical outcomes following one-level posterior lumbar interbody fusion. J Orthop Sci 23:870–877 Otuski B, Fujibayashi S, Tanida S et al (2021) Possible Association of Pedicle Screw Diameter on Pseudoarthrosis Rate After Transforaminal Lumbar Interbody Fusion. World Neurosurg 150:e155–e161 Ekşi MS, Tranriverdi N, Topaloğlu F et al (2025) Higher charlson comorbidity index score correlates with higher rate of pseudoarthrosis following short-segment lumbar interbody fusion surgery. Eur Spine J 34:215–224 Zhao AY, Agarwal AR, Durand WM et al (2023) Prior Fragility Fractures are Associated With a Higher Risk of Bone Health-Related Complications Within Eight Years Following Lumbar Fusion. Spine(Phila Pa 1976) 49(15):1046–1051. 10.1097/BRS.0000000000004867 Fujibayashi S, Takemoto M, Izeki M et al (2012) Does the Formation of Vertebral Endplate Cysts Predict Nonunion After Lumbar Interbody Fusion? Spine(Phila Pa 1976) 37(19):E1197–E1202. 10.1097/BRS0b013e31825d26d7 Segi N, Nakashima H, Shinjo R et al (2024) Trabecular Bone Remodeling as a New Indicator of Osteointegration After Posterior Lumbar Interbody fusion. Global Spine J 14(1):25–32. 10.1177/21925682221090484 Segi N, Nakashima H, Ito S et al (2025) Trabecular Bone Remodeling after Lateral Lumbar Interbody Fusion: Indirect Findings for Stress Transmission betwrrn Vertebrae after Spinal Fusion Surgery. Spine Surg Relat Res 9(1):51–60 Hasegawa Y, Kanayama M, Oha F et al (2022) Patterns of Vertebral Bone Marrow Edema in the Normal Healing Process of Lumbar Interbody Fusion: Baseline Data for Diagnosis of Pathological Events. Spine(Phila Pa 1976) 48(5):358–363. 10.1097/BRS.0000000000004534 Voormolen MHJ, van Rooij WJ, van der Graff Y et al (2006) Bone Marrow Edema in Osteoporotic Vertebral Compression Fractures after Percutaneous Vertebroplasty and Relation with Clinical Outcome. AJAR Am J Neuroradiol 27(5):983–988 Brinckman MA, Chau C, Ross JS (2015) Marrow edema variability in acute spine fractures. Spine J 15:454–460 Taljanovic MS, Graham AR, Benjamin JB et al (2008) Bone marrow edema pattern in advanced hip osteoarthritis: quantitative assessment with magnetic resonance imaging and correlation with clinical examination, radiographic findings, and histopathology. Skelet Radiol 37(5):423–431. 10.1007/s00256-008-0446-3 Zhang Y, Qi H, Zhang Y, Wang J et al (2021) Vertebral bone marrow edema in magnetic resonance imaging correlates with bone healing histomorphometry in (sub)acute osteoporotic vertebral compression fracture. Eur Spine J 30(9):2708–2717. 10.1007/s00586-021-06814-3 Pravatà E (2018) CASE25 Vertebral Body Microfractures / Bone Marrow Edema. Clinical Imaging of Spinal Trauma A Case-Based Approach . 54–55. https://doi.org/10.1017/9781139871372.025 Boonsirikamchai W, Wilartratsami S, Ruangchainikom M et al (2024) Pseudarthrosis risk factors in lumbar fusion: a systematic review and meta-analysis. BMC Musculoskelet Disord 25:433 Chen Q, Ai Y, Huang Y, Li Q et al (2023) MRI-based Endplate Bone Quality score independently predicts cage subsidence following transforaminal lumbar interbody fusion. Spine J 23(11):1652–1658. 10.1016/j.spinee.2023.07.002 Ai Y, Zhu C, Chen Q et al (2024) Comparison of predictive value for cage subsidence between MRI based endplate bone quality and vertebral bone quality scores following transforaminal lumbar interbody fusion: a retrospective propensity-matched study. Spine J 24(6):1046–1055. 10.1016/j.spinee.2024.01.014 Hu YH, Chou JH, Yeh YC et al (2025) The MRI-based vertebral bone quality score is a predictor of pedicle screw loosening following instrumented posterior lumbar fusion. Sci Rep 15(1):1696. 10.1038/s41598-025-85625-8 Shi H, Wang XH, Zhu L et al (2022) Intraoperative Endplate Injury Following Transforaminal Lumbar Interbody Fusion. World Neurosurg 168:e110–e118. 10.1016/j.wneu.2022.09.055 Kang TH, Chung ST, Seo IW et al (2025) Bone turnover markers are risk factors for endplate injuries during lumbar interbody fusion: a retrospective case-control study. J Orthop Surg Res 20(1):192. 10.1186/s13018-025-05585-7 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Reviews received at journal 28 Apr, 2026 Reviewers agreed at journal 27 Apr, 2026 Reviews received at journal 10 Apr, 2026 Reviewers agreed at journal 07 Apr, 2026 Reviewers invited by journal 06 Apr, 2026 Editor assigned by journal 28 Jan, 2026 Submission checks completed at journal 28 Jan, 2026 First submitted to journal 19 Jan, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8644981","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":619257158,"identity":"f6c91e05-8068-4307-926b-779b843530ec","order_by":0,"name":"Yukitoshi Shimamura","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABBklEQVRIiWNgGAWjYDACCcYGMM3P3tj++UcFkMXM3ECcFsmew8eYGc6AtDAS0gKlDW6kpTEztoGYBLTIz25u3fAz53DizIYcs8eF82qj+duBWn5UbMOpxeDOwbabvdsOJ/YznDE3nrnteO6Mw4wNjD1nbuPWIpHYdoMXqGVmY4+BBO+2Y7kNQC1AF+LWIj8jse3mX6CWDYd5gFrmHMudT0gLw43EttsgWzYcY0uT5m2oyd1ASIsBSIvstnTjmT3Mhw1nHDuQuxGo5SA+v8jPSH928+02a9l++YeNDz7U1OXOO3/44IMfFXgcBgWODRD6MJg8QFA9ENhD6TpiFI+CUTAKRsEIAwBLGWneyM7fHAAAAABJRU5ErkJggg==","orcid":"","institution":"Hakodate Central General Hospital","correspondingAuthor":true,"prefix":"","firstName":"Yukitoshi","middleName":"","lastName":"Shimamura","suffix":""},{"id":619257159,"identity":"3595513d-23f9-4aab-a116-52aac538afd7","order_by":1,"name":"Masahiro Kanayama","email":"","orcid":"","institution":"Hakodate Central General Hospital","correspondingAuthor":false,"prefix":"","firstName":"Masahiro","middleName":"","lastName":"Kanayama","suffix":""},{"id":619257160,"identity":"0a6ec73d-9aa5-42fb-a09f-d2ff467ac8a7","order_by":2,"name":"Fumihiro Oha","email":"","orcid":"","institution":"Hakodate Central General Hospital","correspondingAuthor":false,"prefix":"","firstName":"Fumihiro","middleName":"","lastName":"Oha","suffix":""},{"id":619257161,"identity":"a10004fd-5dfb-440b-90b5-cfe852164ed3","order_by":3,"name":"Michihaya Kono","email":"","orcid":"","institution":"Hakodate Central General Hospital","correspondingAuthor":false,"prefix":"","firstName":"Michihaya","middleName":"","lastName":"Kono","suffix":""},{"id":619257162,"identity":"003eb425-eae8-418e-9d18-4586a472f73d","order_by":4,"name":"Ryo Fujita","email":"","orcid":"","institution":"Hakodate Central General Hospital","correspondingAuthor":false,"prefix":"","firstName":"Ryo","middleName":"","lastName":"Fujita","suffix":""},{"id":619257163,"identity":"fafae97b-6896-402b-89bc-a928ea81e5cd","order_by":5,"name":"Reiji Yamamoto","email":"","orcid":"","institution":"Hakodate Central General Hospital","correspondingAuthor":false,"prefix":"","firstName":"Reiji","middleName":"","lastName":"Yamamoto","suffix":""},{"id":619257164,"identity":"e41c792c-9ab4-4f6c-bf6c-22e794983ad2","order_by":6,"name":"Shogo Fukase","email":"","orcid":"","institution":"Hakodate Central General Hospital","correspondingAuthor":false,"prefix":"","firstName":"Shogo","middleName":"","lastName":"Fukase","suffix":""},{"id":619257165,"identity":"9feae856-ec96-457e-acf5-a7b616d4acfd","order_by":7,"name":"Kohei Shiota","email":"","orcid":"","institution":"Hakodate Central General Hospital","correspondingAuthor":false,"prefix":"","firstName":"Kohei","middleName":"","lastName":"Shiota","suffix":""},{"id":619257166,"identity":"d30221ac-1abd-4d36-a725-922234853233","order_by":8,"name":"Tsutomu Endo","email":"","orcid":"","institution":"Hakodate Central General Hospital","correspondingAuthor":false,"prefix":"","firstName":"Tsutomu","middleName":"","lastName":"Endo","suffix":""},{"id":619257167,"identity":"999214f2-ef29-4c1a-bb6d-bc94a4351fc3","order_by":9,"name":"Tomoyuki Hashimoto","email":"","orcid":"","institution":"Hakodate Central General Hospital","correspondingAuthor":false,"prefix":"","firstName":"Tomoyuki","middleName":"","lastName":"Hashimoto","suffix":""},{"id":619257168,"identity":"9d7ff69b-1fe9-461d-8562-f320d727be1d","order_by":10,"name":"Norimasa Iwasaki","email":"","orcid":"","institution":"Hokkaido University","correspondingAuthor":false,"prefix":"","firstName":"Norimasa","middleName":"","lastName":"Iwasaki","suffix":""}],"badges":[],"createdAt":"2026-01-20 04:58:07","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8644981/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8644981/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":106706518,"identity":"44a53f57-04f8-4ea7-ba2f-888d32f7bbd9","added_by":"auto","created_at":"2026-04-12 09:10:20","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":218528,"visible":true,"origin":"","legend":"\u003cp\u003eThe examples of vertebral endplate cyst. a) the occurrence of vertebral endplate cyst, b) no vertebral endplate cysts. White arrow suggests vertebral endplate cyst.\u003c/p\u003e","description":"","filename":"Fig.1.png","url":"https://assets-eu.researchsquare.com/files/rs-8644981/v1/11ffb2a34a84e07d4d922a97.png"},{"id":106706521,"identity":"d9108beb-6c99-40bf-a3bb-f44f7e300edd","added_by":"auto","created_at":"2026-04-12 09:10:23","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":234171,"visible":true,"origin":"","legend":"\u003cp\u003eThe examples of trabecular bone remodeling. a) the existence of trabecular bone remodeling, b) no trabecular bone remodeling. White arrow suggests trabecular bone remodeling.\u003c/p\u003e","description":"","filename":"Fig.2.png","url":"https://assets-eu.researchsquare.com/files/rs-8644981/v1/fb3994bd0263d9457ba00ccd.png"},{"id":106706535,"identity":"423116d2-f16f-4b61-8849-7c4be926d8c1","added_by":"auto","created_at":"2026-04-12 09:10:24","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":271307,"visible":true,"origin":"","legend":"\u003cp\u003eThe definition of bone marrow edema on early postoperative MRI. a) the presence of bone marrow edema, b) the absence of bone marrow edema. White arrow suggests bone marrow edema.\u003c/p\u003e","description":"","filename":"Fig.3.png","url":"https://assets-eu.researchsquare.com/files/rs-8644981/v1/4281699277b16c4fc9959471.png"},{"id":106728489,"identity":"6b6bda73-ff59-43c9-8222-fc6549bfe201","added_by":"auto","created_at":"2026-04-12 18:42:58","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":82270,"visible":true,"origin":"","legend":"\u003cp\u003eSuccessful fusion rate\u003c/p\u003e","description":"","filename":"Fig.4.png","url":"https://assets-eu.researchsquare.com/files/rs-8644981/v1/e2e9298e00339965ecb4bedc.png"},{"id":106706536,"identity":"3b0d3823-9ef6-42f4-8e9d-0cc10702d410","added_by":"auto","created_at":"2026-04-12 09:10:25","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":273339,"visible":true,"origin":"","legend":"\u003cp\u003eThe examples of three patterns of bone marrow edema. a) anterior corner pattern, b) around-the-cage pattern, c) diffuse pattern.\u003c/p\u003e","description":"","filename":"Fig.5.png","url":"https://assets-eu.researchsquare.com/files/rs-8644981/v1/71284e48fecf326264310c15.png"},{"id":106728941,"identity":"ac46180e-737c-4414-b3f6-cdda9f7c7fcb","added_by":"auto","created_at":"2026-04-12 18:46:39","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2225908,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8644981/v1/c95e416e-56df-4921-89ce-2bd36537ed58.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Absence of Bone Marrow Edema on Early Postoperative MRI Predicts Fusion Outcome After Single-Level Lumbar Interbody Fusion","fulltext":[{"header":"Introduction","content":"\u003cp\u003eLumbar interbody fusion widely performed to address degenerative lumbar spine conditions [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e], especially in aging population. As life expectancy increases globally, the prevalence of lumbar pathologies has risen, leading to greater demand for fusion surgeries [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan additionalcitationids=\"CR4\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Although these procedures often provide clinical benefits such as pain relief and neurological improvement, complications remain. Among them, pseudoarthrosis\u0026mdash;a failure of osseous union\u0026mdash;continues to pose significant clinical challenges, frequently resulting in implant instability, persistent symptoms, and need for revision surgery [\u003cspan additionalcitationids=\"CR7\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eNumerous studies have examined risk factors for pseudoarthrosis, including age, smoking status, low bone mineral density (BMD), and multilevel fusions [\u003cspan additionalcitationids=\"CR10 CR11 CR12 CR13\" citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e], yet accurate prediction of fusion success remain difficult. Postoperative imaging, particularly computed tomography (CT), has been used to assess signs such as vertebral endplate cyst (VEC) [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e], trabecular bone remodeling [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e], and cage subsidence, which may reflect fusion progression or failure. However, these markers typically emerge several months after surgery, limiting their value for early prediction. In contrast, magnetic resonance imaging (MRI), though commonly used for preoperative evaluation, has been investigated for its utility in predicting postoperative fusion. Clinical observations have revealed that some patients exhibit bone marrow edema near the fused segment during early postoperative MRI, while others do not.\u003csup\u003e18\u003c/sup\u003e Bone marrow edema is generally considered to reflect inflammation, microdamage in the vertebral body [\u003cspan additionalcitationids=\"CR19 CR20 CR21 CR22\" citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e], but its relationship with bone fusion is still unclear; it has yet to be determined whether bone marrow edema represents favorable biological remodeling promoting osseous integration, or instead indicates disruptive mechanical instability that impairs bone healing. Prior reports lacked systematic evaluation of the prognostic implications over time, and thus, further investigation is warranted to clarify whether the presence or absence of bone marrow edema serves as a meaningful predictor of fusion outcomes.\u003c/p\u003e \u003cp\u003e This study was designed to test the hypothesis that early postoperative bone marrow edema, identified by MRI, is predictive of subsequent fusion status evaluated by CT. By determining the clinical relevance of this early imaging feature, the study aims to establish a new prognostic tool that can guide postoperative management more effectively. Identification of bone marrow edema as an early marker may allow for timely clinical interventions such as adjusting brace protocols, optimizing imaging surveillance, or initiating osteoanabolic therapy. Expanding the prognostic role of MRI could improve outcomes in lumbar interbody fusion by enabling tailored and anticipatory postoperative care.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eStudy Design and Ethical Approval\u003c/h2\u003e \u003cp\u003e This retrospective observational study was conducted at our Spine Center and was approved by the clinical ethics committee (Approval No: 2025-04). All procedures adhered to the principles of the Declaration of Helsinki and relevant guidelines. Informed consent was waived due to the study\u0026rsquo;s retrospective nature and anonymous of patient data.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003ePatient Selection\u003c/h3\u003e\n\u003cp\u003eMedical records and imaging data of patients who underwent one-segment lumbar interbody fusion at a single institution between April 2020 and May 2023. A total of 152 patients met the following inclusion criteria: 1) neurological symptoms caused by focal stenosis, 2) surgical procedure: posterior lumbar interbody fusion (PLIF) or transforaminal lumbar interbody fusion (TLIF), 3) availability of one-year follow-up, 4) MRI was performed three weeks after surgery, (5) CT imaging scan obtained at 3, 6 and 12 postoperative months. Exclusion criteria were as follows; 1) follow-up period less than one year, 2) History of prior spinal fusion surgery, 3) surgery performed for traumas or spinal tumors, (4) preoperative Modic change in the fused segment, (5) age under 18 years.\u003c/p\u003e \u003cp\u003eDemographic valuables collected included age, sex, body mass index (BMI), smoking status, the presence of diabetes mellitus (DM), lumbar and femoral bone BMD (T-score), and fusion level.\u003c/p\u003e\n\u003ch3\u003eSurgical procedure\u003c/h3\u003e\n\u003cp\u003eA posterior midline approach was used in all cases. Following exposure of the relevant vertebrae, pedicle screw and rods were placed before decompression. After distraction and temporary fixation, the caudal half of lamina and the inferior articular processes of the cranial vertebra were removed, and ligamentum flavum was excised. The intervertebral disc and cartilaginous endplates were cleared, and autologous bone graft was harvested from the resected lamina and processes using a bone mill. Artificial bone was added when necessary. No iliac crest harvesting was performed. Interbody cages were inserted and final fixation was achieved by compressing the pedicle screws. A cross-link was installed in all cases unless anatomically restricted. Postoperative ambulation with a lumbar corset (MAXBELTme2, SIGMAX, Japan) began on the first day after surgery.\u003c/p\u003e\n\u003ch3\u003eRadiographic parameters\u003c/h3\u003e\n\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eCT Assessment\u003c/h2\u003e \u003cp\u003eCT scan was performed at 3, 6, and 12 postoperative months (Aquilion 64, Canon, Japan / Aquilion ONE, Canon, Japan). The following parameters were recorded: \u003cb\u003ea) fusion status\u003c/b\u003e: defined as continuous bony bridging across the intervertebral space on both coronal or sagittal images, \u003cb\u003eb) cage subsidence\u003c/b\u003e: defined as \u0026ge;\u0026thinsp;2 mm downward migration of the interbody cage into the vertebral body, \u003cb\u003ec) VEC\u003c/b\u003e: cystic lesions observed at the vertebral endplates of the fused segment. VEC is used as the predictor for non-union (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e) [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. \u003cb\u003ed) TBR\u003c/b\u003e: radiographic changes in trabecular patterns of adjacent vertebral bodies, indicating remodeling activity. TBR is known as the predictive findings of successful interbody fusion (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e) [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. For all CT findings, evaluation was performed by two spine surgeons (Y.S. and K.S.). In cases of disagreement, a final decision was reached by consensus.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eMRI finding\u003c/h2\u003e \u003cp\u003eAll patients underwent MRI examination three weeks after surgery using the T system (Signa HDxt\u003csup\u003e\u0026reg;\u003c/sup\u003e; GE Medical Systems Information Technologies Inc., USA). Bone marrow edema was defined as a low-intensity area in the vertebral body on T1-weighted images (TR 500 ms, TE 10 ms; slice thickness 5mm; gap 1 mm; number of excitations 2; echo train 3) (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). Evaluation was independently performed by two spine surgeons. To assess intra-observer reliability, the same examiner (Y.S.) performed measurements twice with an interval of more than one week. Inter-observer reliability was assessed using independent measurement performed by two examiners (Y.S. and K.S.). In cases of disagreement, a final decision was reached by consensus. Intra-observer reliability of bone marrow edema was substantial; kappa coefficient was 0.77 (0.65\u0026ndash;0.89). Inter-observer reliability was moderate; kappa coefficient was 0.57 (0.41\u0026ndash;0.74).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eAdditional surgery\u003c/h3\u003e\n\u003cp\u003eWe reviewed the type and cause of additional surgeries performed within one year after the initial surgery based on medical records.\u003c/p\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eThe patients were divided into edema group (with bone marrow edema) and non-edema group (without edema). We compared measured valuables between the two groups. As a sub-analysis, fusion status, cage subsidence, VEC and TBR were analyzed according to the edema patterns reported by Hasegawa et al.\u003csup\u003e18\u003c/sup\u003e Pearson chi-square analysis was performed to assess the statistical significance of categorical data, including sex, smoking status, DM, fusion status, the occurrence of VEC, TBR, and cage subsidence. Continuous data were compared between the two groups using unpaired t-test. Inter- and intra-observer reliability were assessed using Cohen\u0026rsquo;s kappa (κ) coefficient. Cohen\u0026rsquo;s κ coefficient was interpreted as follows: \u0026lt; 0.00: poor, 0.00-0.20: Slight, 0.21\u0026ndash;0.40: Fair, 0.41\u0026ndash;0.60: Moderate, 0.61\u0026ndash;0.80: Substantial, 0.81-1.00: Almost Perfect. All analyses were performed using Bellcurve for Excel ver. 4.08 (Social Survey Research Information Co., Ltd. Japan), and a p-value\u0026thinsp;\u0026lt;\u0026thinsp;0.05 was considered significant.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eMissing data\u003c/h2\u003e \u003cp\u003eThe following items had missing data: lumbar BMD, 3.9% (6/152); femoral neck BMD, 4.6% (7/152). In group comparisons, missing data were treated as blanks.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003ePatients Demographics\u003c/h2\u003e \u003cp\u003ePatients included in this study were 74 men and 78 women with a mean age of 68.8 years (30\u0026ndash;88 years) at the initial surgery. Smoking status was classified as follows: non-smoker, former smoker (who had quit smoking at least 6 months before surgery), and current smoker. There were 82 non-smokers, 28 former smokers, 34 current smokers. The rate of DM was 22.2% (34 /153 patients). Mean lumbar BMD was 0.1 (-3.2\u0026ndash;5) and mean femoral neck BMD was \u0026minus;\u0026thinsp;1.2 (-3.9\u0026ndash;2.1). The fusion segments were distributed as follows: L1/2 in 4 patients, L2/3 in 3, L3/4 in 25, L4/5 in 81, L5/6 in 1, L5/S1 in 38 (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003e\u003cb\u003ePatient characteristics (N\u0026thinsp;=\u0026thinsp;152)\u003c/b\u003e\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"2\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge (years)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e68.8\u0026thinsp;\u0026plusmn;\u0026thinsp;11.5\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSex (men / women)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e74 / 78\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBMI (kg/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e25\u0026thinsp;\u0026plusmn;\u0026thinsp;3.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSmoking status, n (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNon smoker\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e82 (53.9%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFormer smoker\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e28 (18.4%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCurrent smoker\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e34 (22.4%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eUnclear\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e8 (5.3%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eThe history of DM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e34 (22.4%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBMD (T-score)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLumbar\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.1\u0026thinsp;\u0026plusmn;\u0026thinsp;1.7\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemoral neck\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-1.2\u0026thinsp;\u0026plusmn;\u0026thinsp;1.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFusion segment\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eL1/2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4 (2.6%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eL2/3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 (2%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eL3/4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e25 (16.4%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eL4/5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e81 (53.3%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eL5/6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 (0.7%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eL5/S1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e38 (25%)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"2\"\u003eData are shown as means\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviations or numbers (percentages).\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"2\"\u003eBMI: body mass index, DM: diabetes mellitus, BMD: bone mineral density\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eA total of 152 patients were included in the final analysis. Among them, 117 patients exhibited bone marrow edema on early postoperative MRI at three weeks and were assigned to the edema group, while 35 patients without edema comprised the non-edema group. The non-edema group accounted for 23% of the cohort. No significant differences were observed between groups in terms of age, sex distribution, BMI, smoking status, diabetes history, lumbar BMD, and femoral neck BMD (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003ePatient characteristics of edema group and non-edema group\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eedema group\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003enon-edema group\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePatients\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e117\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge (years)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e68.7\u0026thinsp;\u0026plusmn;\u0026thinsp;11.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e69.2\u0026thinsp;\u0026plusmn;\u0026thinsp;12.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.797\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSex\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003emen / women\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e59/58\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e15/20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.432\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBMI (kg/m\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e24.9\u0026thinsp;\u0026plusmn;\u0026thinsp;3.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e25.2\u0026thinsp;\u0026plusmn;\u0026thinsp;4.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.758\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSmoking status\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.127\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNon smoker\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e51.3% (60)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e62.9% (22)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFormer smoker\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e16.2% (19)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e25.7% (9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCurrent smoker\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e25.6% (30)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11.4% (4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eThe history of DM\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e20.5% (24)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e28.6% (10)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.316\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBMD (T-score)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLumbar\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.1\u0026thinsp;\u0026plusmn;\u0026thinsp;1.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.3\u0026thinsp;\u0026plusmn;\u0026thinsp;2.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.429\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFemoral neck\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-1.2\u0026thinsp;\u0026plusmn;\u0026thinsp;1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-1.2\u0026thinsp;\u0026plusmn;\u0026thinsp;1.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.885\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eData are shown as means\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviations or percentages (numbers).\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eBMI: body mass index, DM: diabetes mellitus, BMD: bone mineral density\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003eBone Fusion Status\u003c/h2\u003e \u003cp\u003eCT-based evaluation demonstrated significantly higher fusion rates in the non-edema group across all time points. At 3 months postoperatively, fusion was achieved in 85.7% of non-edema patients versus 31.6% of edema patients (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001). At 6 months, rates were 91.2% versus 47.9%, respectively (p\u0026thinsp;\u0026lt;\u0026thinsp;0.001), and 12 months, 91.2% in the non-edema group versus 72.6% in the non-edema group (p\u0026thinsp;=\u0026thinsp;0.024), confirming a consistent trend favoring patients without postoperative bone marrow edema (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003eCage subsidence\u003c/h2\u003e \u003cp\u003eCage subsidence occurred exclusively in the edema group. At 3months, 20.5% of edema patients experienced subsidence compared to 0% in the non-edema group (p\u0026thinsp;=\u0026thinsp;0.004). The difference remained significant at 6 months (21.4% vs. 0%, p\u0026thinsp;=\u0026thinsp;0.003) and 12 months (22.2% vs. 0%, p\u0026thinsp;=\u0026thinsp;0.002), indicating a strong association between bone marrow edema and postoperative mechanical instability (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eCT findings of edema group and non-edema group\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eedema group\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003enon-edema group\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eThe occurrence of VEC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3 months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e28.2% (33)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5.7% (2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.006\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e6 months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e29.9% (35)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e11.4% (4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.026\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e12 months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e26.5% (31)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e8.6% (3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.024\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eThe occurrence of TBR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3 months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e37.6% (44)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e54.2% (19)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.079\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e6 months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e47.9% (56)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e60% (21)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.224\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e12 months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e39.3% (46)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e62.9% (22)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.017\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCage subsidence\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3 months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e20.5% (24)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0% (0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.004\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e6 months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e21.4% (25)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0% (0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.003\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e12 months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e22.2% (26)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0% (0)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.002\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eData are shown as percentages (numbers).\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003eVEC: vertebral endplate cyst, TBR: trabecular bone remodeling\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec16\" class=\"Section2\"\u003e \u003ch2\u003eVEC occurrence\u003c/h2\u003e \u003cp\u003eThe incidence of VEC was significantly lower in the non-edema group. At 3 months, VEC appeared in 5.7% of non-edema patients compared to 28.2% in the edema group (p\u0026thinsp;=\u0026thinsp;0.006). This pattern persisted at 6 months (11.4% vs. 29.9%, p\u0026thinsp;=\u0026thinsp;0.026), and at 12 months (8.6% vs. 26.5%, p\u0026thinsp;=\u0026thinsp;0.024) (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec17\" class=\"Section2\"\u003e \u003ch2\u003eTBR\u003c/h2\u003e \u003cp\u003eAlthough not statistically significant at early points (at 3 months: 54.2% vs. 37.6%, p\u0026thinsp;=\u0026thinsp;0.079; 6 months 60% vs. 47.6%, p\u0026thinsp;=\u0026thinsp;0.224), TBR tended to be more frequent in the non-edema group and became significant at 12 months (62.9% vs. 39.3%, p\u0026thinsp;=\u0026thinsp;0.017) (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec18\" class=\"Section2\"\u003e \u003ch2\u003eComparison among edema patterns\u003c/h2\u003e \u003cp\u003eHasegawa et al. reported that bone marrow edema were divided into three patterns: 1) anterior corner pattern, 2) around-the-cage pattern, 3) diffuse pattern (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e) [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. In present study, 42 patients (27.6%) were classified into anterior corner pattern, 66 (43.4%) into around-the-cage pattern, and nine (5.9%) into diffuse pattern. No statistically significant differences were observed in fusion status among three groups, but diffuse pattern showed following tendencies: occurrence of early postoperative cage subsidence and VEC, and lower incidence of TBR compared to other patterns (Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eComparison among three patterns\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAnterior corner\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAround-the-cage\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ediffuse\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003ep\u003c/em\u003e-value\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePatients\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e42\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSuccessful fusion\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3 months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21.4% (9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e39.4% (26)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e33.3% (3)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.151\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e6 months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e48.8% (20)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e30.3% (20)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e44.4% (4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.146\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e12 months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e65.9% (27)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e66.7% (44)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e66.7% (6)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.996\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eThe occurrence of VEC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3 months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e19% (8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e24.2% (16)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e44.4% (4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.268\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e6 months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e22% (9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e25.8% (17)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e44.4% (4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.378\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e12 months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e19.5% (8)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e18.2% (12)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e22.2% (2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.953\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eThe occurrence of TBR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3 months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e38.1% (16)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e37.9% (25)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e11.1% (1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.272\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e6 months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e46.3% (19)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e37.9% (25)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e11.1% (1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.141\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e12 months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e41.5% (17)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e37.9% (25)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e11.1% (1)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.228\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCage subsidence\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3 months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21.4% (9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e13.6% (9)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e44.4% (4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.074\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e6 months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e29.3% (12)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e16.7% (11)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e44.4% (4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.096\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e12 months\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e31.7% (13)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e18.2% (12)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e44.4% (4)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.109\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003eData are shown as percentages (numbers).\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003eVEC: vertebral endplate cyst, TBR: trabecular bone remodeling\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec19\" class=\"Section2\"\u003e \u003ch2\u003eAdditional surgery\u003c/h2\u003e \u003cp\u003eAdditional surgery was performed only one patient in the edema group. Extension of spinal segmental fusion surgery was undergone for pedicle fracture and instrumentation failure between 3 and 6 months postoperatively.\u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study demonstrated that absence of bone marrow edema on early postoperative MRI was significantly associated with successful interbody fusion following single-level lumbar interbody fusion surgery. Patients without edema showed higher rates of bony union over time and exhibited favorable radiographic characteristics, including reduced incidence of VEC, increased TBR, and notably, no cage subsidence. These findings support the potential utility of early MRI in postoperative evaluation and highlight the prognostic relevance of bone marrow edema in spinal fusion outcomes.\u003c/p\u003e \u003cp\u003eOur findings raise the possibility that early postoperative changes visible on imaging offer a more accurate reflection of the biomechanical and biological conditions relevant to fusion than clinical and demographic factors present before surgery. Various patient-related risk factors for pseudoarthrosis\u0026mdash;such as age, smoking, and low BMD\u0026mdash;have been widely reported [\u003cspan additionalcitationids=\"CR10 CR11 CR12 CR13\" citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e], but the present study did not identify significant differences in demographic or metabolic variables between the edema and the non-edema groups. Previous investigations have focused primarily on CT-based indicators, such as VEC and TBR, evaluated at later postoperative stage. Fujibayashi, et al. reported that VEC formation on CT at 3 months postoperatively predicted subsequent union status and clarified that the case who has VEC formation on early postoperative CT developed into nonunion [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Segi, et al. reported the relationship between successful interbody fusion and the occurrence of TBR on CT at 3 months postoperatively, and patients with early TBR did not experience pedicle screw cutout nor pseudarthrosis and had significantly fewer VECs than those without early TBR [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. The study concluded that TBR may be a new radiological marker of initial fixation after PLIF. Both of these studies suggest that the possibility of pseudoarthrosis can be predicted at an early postoperative time point, specifically at three months. It is preferable to predict pseudoarthrosis after lumbar interbody fusion surgery as early as possible, as it allows for timely interventions such as extending the duration of brace immobilization, more frequent follow-up evaluations, and the administration of osteoanabolic agents such as parathyroid hormone when appropriate. Although other studies have recommended early postoperative CT for assessment, no reports to date have discussed the potential of early postoperative MRI for predicting bone fusion. The present study demonstrated that bone marrow edema on MRI could predict fusion status at 3 weeks postoperatively. In addition, bone marrow edema was also related to the occurrence of VEC and TBR. From the result of present study, bone marrow edema might represent an imaging finding capable of predicting future successful interbody fusion at an earlier postoperative stage.\u003c/p\u003e \u003cp\u003eThe present study demonstrated that absence of bone marrow edema on early postoperative MRI could predict successful interbody fusion and the inhibited cage subsidence. Recently, MRI has been increasingly used for the preoperative evaluation in spinal instrumentation surgeries; the endplate bone quality (EBQ) score is an MRI-based metric that quantifies signal intensity on T1-weighted images at the vertebral endplates, reflecting structural and compositional changes such as fatty infiltration, sclerosis, or inflammation [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. Chen, et al. investigated whether EBQ score is related to cage subsidence or not; they reported risk of cage subsidence increased significantly with higher EBQ scores and higher EBQ score was an independent factor in predicting subsidence after TLIF [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. Ai, et al. investigated vertebral bone quality (VBQ) score and EBQ score affect the occurrence of cage subsidence after one-segment lumbar interbody fusion [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. Concluding that higher scores in both parameters were associated with increased risk. But few studies evaluated the association between MRI findings and bone union. Hu, et al. reported that a higher VBQ score was an independent risk factor for pedicle screw loosening following instrumented TLIF [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. The results of present study suggested that MRI might be useful for both preoperative and postoperative evaluation.\u003c/p\u003e \u003cp\u003eBone marrow edema may represent a critical intermediary in the cascade leading to impaired bone fusion. Bone marrow edema is reported to be a consequence of local inflammatory reaction or microfractures with resultant edema or hemorrhage [\u003cspan additionalcitationids=\"CR20 CR21 CR22\" citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. Based on these findings, our hypothesis regarding the relationship between bone marrow edema and impaired bone fusion is as follows; interoperative endplate manipulation leads to microdamage or microfracture of vertebral bone or vertebral endplate [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e, \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. In addition, since cage insertion slightly elevates the intervertebral height, mechanical stress is exerted especially on the vertebral endplates around the cage. This damage and stress of vertebral body and endplate may occur inflammatory changes. These inflammatory changes could lead to vertebral endplate cyst formation, hinder bone remodeling, and ultimately impede bone fusion. As a result, slight intervertebral instability may occur, potentially leading to the development of pseudarthrosis.\u003c/p\u003e \u003cp\u003eIn the present study, among the three edema patterns, the diffuse pattern tended to show a higher incidence of early cage subsidence and VEC, as well as a lower incidence of TBR. These tendencies suggest that attention should be paid to the occurrence of early cage subsidence and VEC in diffuse pattern. However, as only nine cases of diffuse pattern were included in present study, further investigations with a larger sample size are needed.\u003c/p\u003e \u003cp\u003eThe present study has several limitations. The single-center design ensured surgical standardization but may limit generalizability. MRI was performed only once at three weeks; serial imaging might offer a more dynamic understanding of edema evolution and its relationship with fusion. Additionally, despite adequate intra- and inter-observer reliability, the subjective nature of edema interpretation warrants standardization of evaluation criteria. Finally, these findings are specific to single-level fusion procedures, and application to multi-level surgeries requires further investigation.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn summary, this study underscores the importance of early bone marrow edema as a radiographic finding and proposes its absence as a potential predictor of successful lumbar interbody fusion. Incorporating early postoperative MRI into routine assessment may provide a more refined and temporally sensitive framework for evaluating fusion trajectory and guiding postoperative management.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that no funds, grants, or other support were received during the preparation of this manuscript.\u0026nbsp;No funding was obtained for this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors have no relevant financial or non-financial interests to disclose.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll authors contributed to the study conception and design. Material preparation, data collection and analysis were performed by Y.S. The first draft of the manuscript was written by Y.S. and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe requirement for informed consent was waived because of the retrospective nature of the study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to publish\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study doesn\u0026rsquo;t contain any images that could identify individuals.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eReisener MJ, Pumberger M, Shue J et al (2020) Trends of lumbar spinal fusion-a literature review. J Spine Surg 6(4):752\u0026ndash;761. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.21037/jss-20-492\u003c/span\u003e\u003cspan address=\"10.21037/jss-20-492\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAbdu WA, Sacks OA, Tosteson ANA et al (2018) Long-Term Results of Surgery Compared With Nonoperative Treatment for Lumbar Degenerative Spondylolisthesis in the Spine Patient Outcomes Research Trial (SPORT). Spine(Phila Pa 1976) 43(23):1619\u0026ndash;1630. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1097/BRS.0000000000002682\u003c/span\u003e\u003cspan address=\"10.1097/BRS.0000000000002682\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRajaee SS, Bae HW, Kanim LEA et al (2012) Spinal Fusion in the United States. Spine(Phila Pa 1976) 37:67\u0026ndash;76. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1302/0301-620X.96B6\u003c/span\u003e\u003cspan address=\"10.1302/0301-620X.96B6\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. Analysis of Trends From 1998 to 2008\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMartin BI, Mirza SK, Spina N et al (2018) Trends in Lumbar Fusion Procedure Rates and Associated Hospital Costs for Degenerative Spinal Diseases in the United States, 2004 to 2015. Spine(Phila Pa 1976) 44(5):369\u0026ndash;376\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eImajo Y, Taguchi T, Yone K et al (2015) Japanese 2011 nationwide survey on complications from spine surgery. J Orthop Sci 20:38\u0026ndash;54. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s00776-014-0656-6\u003c/span\u003e\u003cspan address=\"10.1007/s00776-014-0656-6\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMakino T, Kaito T, Fujiwara H et al (2014) Does fusion status after posterior interbody fusion affect patient-based QOL outcomes? An evaluation performed using a patient-based outcome measure. J Orthop Sci 19:707\u0026ndash;712. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s00776-014-0591-6\u003c/span\u003e\u003cspan address=\"10.1007/s00776-014-0591-6\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTsutsumimoto T, Shimogata M, Yoshimura Y et al (2008) Union versus nonunion after posterolateral lumbar fusion: a comparison of long-term surgical outcomes in patients with degenerative lumbar spondylosis. Eur Spine J 17:1107\u0026ndash;1112. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s00586-008-0695-9\u003c/span\u003e\u003cspan address=\"10.1007/s00586-008-0695-9\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChun DS, Baker KC, Hsu WK (2015) Lumbar pseudarthrosis: a review of current diagnosis and treatment. Nuerosurg Focus 39(4):E10. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3171/2015.7.FOCUS15292\u003c/span\u003e\u003cspan address=\"10.3171/2015.7.FOCUS15292\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePhan K, Fedhil M, Chang N et al (2018) Effect of Smoking Status on Successful Arthrodesis, Clinical Outcome, and Complications After Anterior Lumbar Interbody Fusion (ALIF). World Neurosurg 110:e998\u0026ndash;e1003\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKonomi T, Yasuda A, Fumiyoshi K et al (2020) Incidences andRisk Factors for Postoperative Non-Union after Posterior Lumbar Interbody Fusion with Closed-Box Titanium Spacers. Asian Spine J 14(1):106\u0026ndash;112\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCho JH, Hwang CJ, Kim H et al (2018) Effect of osteoporosis on the clinical and radiographical outcomes following one-level posterior lumbar interbody fusion. J Orthop Sci 23:870\u0026ndash;877\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOtuski B, Fujibayashi S, Tanida S et al (2021) Possible Association of Pedicle Screw Diameter on Pseudoarthrosis Rate After Transforaminal Lumbar Interbody Fusion. World Neurosurg 150:e155\u0026ndash;e161\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEkşi MS, Tranriverdi N, Topaloğlu F et al (2025) Higher charlson comorbidity index score correlates with higher rate of pseudoarthrosis following short-segment lumbar interbody fusion surgery. Eur Spine J 34:215\u0026ndash;224\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhao AY, Agarwal AR, Durand WM et al (2023) Prior Fragility Fractures are Associated With a Higher Risk of Bone Health-Related Complications Within Eight Years Following Lumbar Fusion. Spine(Phila Pa 1976) 49(15):1046\u0026ndash;1051. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1097/BRS.0000000000004867\u003c/span\u003e\u003cspan address=\"10.1097/BRS.0000000000004867\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFujibayashi S, Takemoto M, Izeki M et al (2012) Does the Formation of Vertebral Endplate Cysts Predict Nonunion After Lumbar Interbody Fusion? Spine(Phila Pa 1976) 37(19):E1197\u0026ndash;E1202. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1097/BRS0b013e31825d26d7\u003c/span\u003e\u003cspan address=\"10.1097/BRS0b013e31825d26d7\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSegi N, Nakashima H, Shinjo R et al (2024) Trabecular Bone Remodeling as a New Indicator of Osteointegration After Posterior Lumbar Interbody fusion. Global Spine J 14(1):25\u0026ndash;32. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1177/21925682221090484\u003c/span\u003e\u003cspan address=\"10.1177/21925682221090484\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSegi N, Nakashima H, Ito S et al (2025) Trabecular Bone Remodeling after Lateral Lumbar Interbody Fusion: Indirect Findings for Stress Transmission betwrrn Vertebrae after Spinal Fusion Surgery. Spine Surg Relat Res 9(1):51\u0026ndash;60\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHasegawa Y, Kanayama M, Oha F et al (2022) Patterns of Vertebral Bone Marrow Edema in the Normal Healing Process of Lumbar Interbody Fusion: Baseline Data for Diagnosis of Pathological Events. Spine(Phila Pa 1976) 48(5):358\u0026ndash;363. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1097/BRS.0000000000004534\u003c/span\u003e\u003cspan address=\"10.1097/BRS.0000000000004534\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVoormolen MHJ, van Rooij WJ, van der Graff Y et al (2006) Bone Marrow Edema in Osteoporotic Vertebral Compression Fractures after Percutaneous Vertebroplasty and Relation with Clinical Outcome. AJAR Am J Neuroradiol 27(5):983\u0026ndash;988\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBrinckman MA, Chau C, Ross JS (2015) Marrow edema variability in acute spine fractures. Spine J 15:454\u0026ndash;460\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTaljanovic MS, Graham AR, Benjamin JB et al (2008) Bone marrow edema pattern in advanced hip osteoarthritis: quantitative assessment with magnetic resonance imaging and correlation with clinical examination, radiographic findings, and histopathology. Skelet Radiol 37(5):423\u0026ndash;431. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s00256-008-0446-3\u003c/span\u003e\u003cspan address=\"10.1007/s00256-008-0446-3\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang Y, Qi H, Zhang Y, Wang J et al (2021) Vertebral bone marrow edema in magnetic resonance imaging correlates with bone healing histomorphometry in (sub)acute osteoporotic vertebral compression fracture. Eur Spine J 30(9):2708\u0026ndash;2717. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s00586-021-06814-3\u003c/span\u003e\u003cspan address=\"10.1007/s00586-021-06814-3\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePravat\u0026agrave; E (2018) CASE25 Vertebral Body Microfractures / Bone Marrow Edema. Clinical Imaging of Spinal Trauma \u003cem\u003eA Case-Based Approach\u003c/em\u003e. 54\u0026ndash;55. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1017/9781139871372.025\u003c/span\u003e\u003cspan address=\"10.1017/9781139871372.025\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBoonsirikamchai W, Wilartratsami S, Ruangchainikom M et al (2024) Pseudarthrosis risk factors in lumbar fusion: a systematic review and meta-analysis. BMC Musculoskelet Disord 25:433\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChen Q, Ai Y, Huang Y, Li Q et al (2023) MRI-based Endplate Bone Quality score independently predicts cage subsidence following transforaminal lumbar interbody fusion. Spine J 23(11):1652\u0026ndash;1658. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.spinee.2023.07.002\u003c/span\u003e\u003cspan address=\"10.1016/j.spinee.2023.07.002\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAi Y, Zhu C, Chen Q et al (2024) Comparison of predictive value for cage subsidence between MRI based endplate bone quality and vertebral bone quality scores following transforaminal lumbar interbody fusion: a retrospective propensity-matched study. Spine J 24(6):1046\u0026ndash;1055. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.spinee.2024.01.014\u003c/span\u003e\u003cspan address=\"10.1016/j.spinee.2024.01.014\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHu YH, Chou JH, Yeh YC et al (2025) The MRI-based vertebral bone quality score is a predictor of pedicle screw loosening following instrumented posterior lumbar fusion. Sci Rep 15(1):1696. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/s41598-025-85625-8\u003c/span\u003e\u003cspan address=\"10.1038/s41598-025-85625-8\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShi H, Wang XH, Zhu L et al (2022) Intraoperative Endplate Injury Following Transforaminal Lumbar Interbody Fusion. World Neurosurg 168:e110\u0026ndash;e118. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.wneu.2022.09.055\u003c/span\u003e\u003cspan address=\"10.1016/j.wneu.2022.09.055\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKang TH, Chung ST, Seo IW et al (2025) Bone turnover markers are risk factors for endplate injuries during lumbar interbody fusion: a retrospective case-control study. J Orthop Surg Res 20(1):192. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1186/s13018-025-05585-7\u003c/span\u003e\u003cspan address=\"10.1186/s13018-025-05585-7\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"european-spine-journal","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"esjo","sideBox":"Learn more about [European Spine Journal](http://link.springer.com/journal/586)","snPcode":"586","submissionUrl":"https://submission.springernature.com/new-submission/586/3","title":"European Spine Journal","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"bone marrow edema, fusion status, early postoperative period, lumbar interbody fusion, vertebral endplate cyst, trabecular bone remodeling","lastPublishedDoi":"10.21203/rs.3.rs-8644981/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8644981/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003ePurpose: This study aimed to investigate whether bone marrow edema observed on MRI at three-postoperative week can predict fusion status in a single-level lumbar interbody fusion.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eMethods: This retrospective study included 152 patients who had undergone a single-level lumbar interbody fusion with a minimum of one-year follow-up. All patients underwent MRI at three weeks after surgery and CT scans at 3, 6, and 12 postoperative months. CT scans were used to evaluate fusion status, presence of vertebral endplate cyst (VEC), trabecular bone remodeling (TBR), and cage subsidence. Patients were divided into two groups based on MRI\u0026nbsp;\u003c/p\u003e\n\u003cp\u003efindings: those with bone marrow edema (edema group) and those without (non-edema group). Bone marrow edema was defined as a low-intensity area within the adjacent vertebral bodies on T1-weighted images. Clinical and radiographic outcomes were compared between groups.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;Results: Of 152 patients, 117 were assigned to the edema group and 35 to the non-edema group. The non-edema group demonstrated significantly higher fusion rates at 3, 6, and 12 months postoperatively. Additionally, the non-edema group showed a significantly lower incidence of VEC and a higher frequency of TBR. Cage subsidence was not observed in any patients in the non-edema group, whereas 22.2% of patients in the edema group exhibited cage subsidence at 12 months. Conclusion: Absence of bone marrow edema on MRI assessment at three postoperative week was associated with significantly higher fusion rates. These results suggest that absence of early bone marrow edema may serve as a predictor of successful fusion after single-level lumbar interbody fusion.\u003c/p\u003e","manuscriptTitle":"Absence of Bone Marrow Edema on Early Postoperative MRI Predicts Fusion Outcome After Single-Level Lumbar Interbody Fusion","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-12 09:09:37","doi":"10.21203/rs.3.rs-8644981/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorInvitedReview","content":"","date":"2026-04-29T01:54:29+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"306555984910271725891254210794820781245","date":"2026-04-27T21:51:51+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-04-11T00:41:35+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"83940632027202173128338346667697226908","date":"2026-04-08T00:56:41+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-04-07T01:06:30+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-01-28T06:05:25+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-01-28T06:01:43+00:00","index":"","fulltext":""},{"type":"submitted","content":"European Spine Journal","date":"2026-01-20T04:41:52+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"european-spine-journal","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"esjo","sideBox":"Learn more about [European Spine Journal](http://link.springer.com/journal/586)","snPcode":"586","submissionUrl":"https://submission.springernature.com/new-submission/586/3","title":"European Spine Journal","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"51de126f-625d-47cb-9535-9960675ebe53","owner":[],"postedDate":"April 12th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-04-12T09:09:38+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-12 09:09:37","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8644981","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8644981","identity":"rs-8644981","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}