A new radiological index for the assessment of higher body fat status and lumbar spine degeneration

Which vacuum phenomenon is more predictive for future junctional disorders?: Intradiscal or Intrafacet?

Recent spine studies focused on identifying whether intradiscal vacuum phenomenon (VP) was associated with spinal instability. However, none of them reported a direct association between VP and spinal instability following fusion for degenerative lumbar spine disorders (DSDs), namely junctional disorders. In the present study, we aimed to evaluate whether the VP was predictive for junctional disorders in patients who underwent short-segment lumbar decompression and fusion for DSDs at a tertiary spine center. We retrospectively reviewed prospectively collected database of patients who underwent short-segment decompression and fusion for DSDs. Pre-operative sagittal and axial computed tomography (CT) scans were evaluated in terms of intradiscal and intrafacet VP at all lumbar levels, respectively. Each VP was scored as 1 point. Then, the total VP score was calculated as the sum of intradiscal VP score and intrafacet VP score. Then, we analyzed the possible predictivity of VP for junctional disorders at final follow-ups of the patients operated for short-segment lumbar decompression and fusion. Patients with junctional disorders had significantly higher total and intrafacet VP scores compared to those without junctional disorders. Total VP score had an OR of 1.217 (p = 0.014) and intrafacet VP score had an OR of 1.465 (p = 0.008). The ROC analysis depicted that the cut-offs value for total and intrafacet VP scores to predict junctional disorders following short-segment lumbar decompression and fusion were 1.5 points and 0.5 point, respectively. Vacuum phenomenon could be associated with junctional disorders in patients who underwent short-segment lumbar decompression and fusion for DSD. Intrafacet VP was more important than intradiscal VP in predicting junctional disorders. Proper surgical planning including the evaluation of both intrafacet and intradiscal VP at all lumbar levels is crucial to decrease the likelihood of junctional disorders.

The Impact of Demographic Characteristics, Obesity, Surgical Level, and Intervertebral Disc Properties on Recurrence of Lumbar Disc Herniation

BACKGROUND

This study focused on identifying factors influencing recurrent lumbar disc herniation (RLDH) by analyzing demographic data, body mass index (BMI), and radiologic disc properties in patients undergoing single-level unilateral lumbar disc herniation surgery.

METHODS

Our retrospective analysis included 2 groups from our clinic: Group 1 (n = 41) with patients experiencing RLDH requiring a second surgery, and Group 2 (n = 73) with patients having a single surgery and no recurrence over at least a 5-year follow-up. We assessed age, sex, diabetes mellitus (DM), hypertension (HT), BMI, Pfirrmann disc degeneration type, herniation types (protrusion, extrusion, and sequestration), and surgical level.

RESULTS

The mean ages of Groups 1 and 2 were 48.93 ± 13.47 and 44.4 ± 11.79 years, respectively, with no significant age difference (P = 0.064). Gender distribution was also not significantly different, with 63.41% males in Group 1 and 56.16% in Group 2 (P = 0.450). DM prevalence was similar in both groups (P = 0.727). Notably, HT was significantly lower in Group 2 (P = 0.018). The average BMI was comparable between groups (P = 0.607), and no significant difference in Pfirrmann disc degeneration scores was observed (P = 0.547). Radiologic disc type distributions did not significantly differ (P = 0.448). Most surgeries in both groups were at the L4-5 level, with no significant differences in surgical levels (P = 0.456).

CONCLUSIONS

We found that factors like gender, age, DM, obesity, surgical level, disc degeneration, and disc types do not significantly impact RLDH. However, the higher occurrence of HT in recurrent cases indicates a potential area for further research.

Erector spinae could be the game changer in surgical decision-making in patients with lumbar spondylolisthesis: a cross-sectional analysis of an age-, sex-, subtype-, level-matched patients with similar spinopelvic parameters received surgical or conservative management

PURPOSE

In this study we aimed to identify whether paraspinal muscle morphology could play a role in surgical decision-making in patients with lumbar spondylolisthesis.

METHODS

We conducted a cross-sectional analysis of a prospectively collected database between January 2013 and May 2023. Consecutive women and men, who visited our outpatient clinics with chronic LBP, neurogenic claudication, and had lumbar spine magnetic resonance imaging (MRI) for their complaints were included into the preliminary dataset. We compared the patients who had conservative management (conservative group) or underwent surgery for lumbar spondylolisthesis (surgical group) in terms of intervertebral disc degeneration, end-plate changes, fatty infiltration in the paraspinal muscles and spinopelvic parameters.

RESULTS

Conservative and surgical groups were similar in terms of severe IVDD and Modic changes at any lumbar level. Surgical group had significantly fattier erector spinae compared to the conservative group. Regression analysis and ROC analysis revealed an OR of 1.088 and a cut-off value of 17 points for fatty infiltration in the erector spinae to predict which patient could undergo surgery for lumbar spondylolisthesis.

CONCLUSION

Each 1-point increment in fatty infiltration in the erector spinae at any lumbar level increased the likelihood of surgery by 8%. Lumbar spondylolisthesis patients with fatty infiltration score for erector spinae at or above 17 were more likely to have surgery. We recommend clinicians to focus on improving erector spinae muscles in patients with lumbar spondylolisthesis.

Exploring the Relationship Between Subcutaneous Fat Index and Neck Pain in Patients with Spinal Cervical Spondylosis: A Retrospective Cohort Study

STUDY DESIGN

Retrospective Cohort Study.

OBJECTIVES

This study measures the subcutaneous fat index (SFI) of the cervical spine in patients with spinal cervical spondylosis using cervical magnetic resonance imaging and explores its relationship with neck pain in patients with spinal cervical spondylosis.

METHODS

In this single-center retrospective study, 298 patients hospitalized for spinal cervical spondylosis between January and June 2021 were initially considered. After applying inclusion and exclusion criteria, 93 patients were enrolled. The cervical magnetic resonance imaging data for these patients were analyzed using A-Site software. The SFI was measured at the median sagittal plane on T2-weighted images. Patients were categorized into 2 groups based on their admission complaints: those with cervical pain and those without it. Differences between these groups were then statistically analyzed.

RESULTS

The mean SFIs with standard deviations for the neck and non-neck pain groups were 36.4% ± 7.7% and 27.0% ± 7.9%, respectively, with a significant difference (P < 0.0001). The SFI was consistently higher across all neck segments in the neck pain group compared to the nonneck pain group (P < 0.05). The 2 groups had no statistically significant difference in the body mass index.

CONCLUSIONS

The SFI provides a more precise assessment of muscle and fat distribution in the posterior cervical region than body mass index and is generally higher in patients with spinal cervical spondylosis who experience neck pain. These findings suggest the importance of early functional exercises postsurgery for potentially improving surgical outcomes in this patient population.

Transforaminal Endoscopic Ventral Stenosis Decompression in Calcified Lumbar Disc Herniation: A Long Term Outcome in 79 Patients

BACKGROUND

Calcified lumbar disc herniations (CLDH) causing calcified ventral stenosis pose a therapeutic challenge to the treating surgeon due to their neural adhesions, location, and hardness.

METHODS

This retrospective study analyzed all the cases of CLDH/calcified ventral stenosis managed by transforaminal endoscopic lumbar discectomy with a minimum follow-up of 24 months. The preoperative images were analyzed for the level, migration; and grade (Lee's migration zones), and location (Michigan State University classification). Detailed surgical technique and intraoperative parameters including the duration of surgery and complications have been recorded. The clinical parameters including visual analog scale (VAS), Oswestry disability index (ODI), length of stay in hospital, days of return to basic work, and patient satisfaction index were analyzed. Postoperatively the images were analyzed for the adequacy of decompression.

RESULTS

The mean VAS for back pain and leg pain was 4.7 ± 2.6 (0-9), and 7.45 ± 2.2 (1-10), respectively. The mean preoperative ODI was 78.2 ± 13.2 (63.2-95.6). Nineteen patients (24%) had neurological deficits preoperatively. The mean duration of surgery was 90.5 ± 15.8 (58-131) minutes. Postoperative magnetic resonance imaging revealed adequate decompression in 97.5% (n = 77). The mean duration of hospital stay was 1.05 ± 0.22 (1-2) days, and the postoperative back and leg pain VAS was 1.14 ± 1.2 (0-3) (P < 0.05) and 1.7 ± 0.5 (0-6) (P < 0.05), respectively. The ODI at final follow-up was 6.5 ± 3.7 (2.2-18) (P < 0.05). Neurological recovery occurred in 17 (89.5%) patients and they returned to basic work/jobs in 19.5 ± 3.3 (14-26) days. The mean patient satisfaction index was 1.18 ± 0.47 (1-2) at a mean follow-up of 5.52 ± 2.91 (2-12.75) years.

CONCLUSIONS

Transforaminal endoscopic lumbar discectomy is a complete, safe, and efficacious procedure in patients with CLDH with earlier recovery considering the surgery is performed with the patient being awake.

Mo-fi-disc scoring system: Towards understanding the radiological tools to better delineate the disease process and enhancing our solutions for low back pain in artificial intelligence era

BACKGROUND

'Mo-fi-disc' is a new scoring system that quantifies degeneration of the lumbar spine and predicts the intensity of low back pain (LBP). However, its association with LBP-related disability is unknown. In the present study, we aimed to analyze whether 'Mo-fi-disc' scoring system could predict LBP-related disability and distinguish patients with LBP from asymptomatic subjects, while the spine medicine marching towards the era of artificial intelligence (AI).

METHODS

This is a cross-sectional analysis of a prospectively collected database. We included age-, gender-, and BMI-matched 132 subjects (patients: 66, asymptomatic subjects: 66). Modic changes (Mo), fatty infiltration in the paraspinal muscles (fi), and intervertebral disc degeneration (disc) were evaluated using 'Mo-fi-disc' scoring system on lumbar spine magnetic resonance imaging. Pain and disability were evaluated with visual analogue scale (VAS) and Oswestry disability index (ODI), respectively.

RESULTS

A Mo-fi-disc score of 5.5 was the most appropriate cut-off value. Mo-fi-disc scoring system had an OR of 1.79 in distinguishing patients with LBP from asymptomatic subjects. One point increment in VAS and ODI had ORs of 1.82 and 1.13 for predicting higher Mo-fi-disc scores.

CONCLUSION

'Mo-fi-disc' scoring system is a useful tool depicting intensity of LBP and LBP-related disability. The cut off value of Mo-fi-disc score is 5.5 to distinguish patients with LBP from asymptomatic subjects. This scoring system, with progressive improvement of its faults, could help clinicians to select appropriate patients for conservative and surgical management in the very near future, in AI-based spine medicine.

IRB APPROVAL NO

ATADEK 2019-12/4.

Association between the Thickness of Lumbar Subcutaneous Fat Tissue and the Presence of Hernias in Adults with Persistent, Non-Traumatic Low Back Pain

We aimed to analyze the association between the average lumbar subcutaneous fat tissue thickness (LSFTT) at each intervertebral level and the presence of hernias in patients with low back pain from an insurance network hospital in Mexico. This observational prospective study included 174 patients with non-traumatic lumbago who underwent magnetic resonance imaging with a 1.5T resonator. Two independent radiologists made the diagnosis, and a third specialist provided a quality vote when needed. The sample size was calculated with a 95% confidence interval using random order selection. Anonymized secondary information was used. Percentages and means with confidence intervals were tabulated. The area under the curve, specificity, and sensitivity of LSFTT were calculated. A regression analysis was performed to analyze the presence of hernias with LSFTT using each intervertebral level as a predictor. The odds of herniation at any intervertebral level increased directly with LSFTT. The average LSFTT predicted the overall presence of hernias; however, the LSFTT at each intervertebral level better predicted hernias for each intervertebral space. The area under the curve for LSFTT in predicting hernias was 68%. In conclusion, the average LSFTT was associated with the overall presence of hernias; patients with more hernias had higher LSFTT values.

The Impacts of Intervertebral Disc Degeneration of the Spine, Alcohol Consumption, Smoking Tobacco Products, and Glycemic Disorders on the Expression Profiles of Neurotrophins-3 and -4

In the etiology of discogenic pain, attention is paid to the role of neurotrophic factors, which include classic neurotrophins (NTs). This study aimed to assess changes in the concentrations of NT-3 and NT-4 in the intervertebral discs (IVDs) of the lumbosacral (L/S) spine depending on the advancement of degenerative changes, pain severity, habits, and comorbidities. The study group included 113 patients who underwent microdiscectomy due to degenerative IVD disease of the L/S spine. The severity of degenerative IVD changes was assessed using the five-point Pfirrmann scale, and the pain intensity was assessed according to the visual analog scale (VAS). In turn, the control group included 81 participants from whom IVDs of the L/S section of the spine were collected post-mortem during forensic autopsy or organ donation. At the mRNA level, we noted NT-3 overexpression in the test samples compared with the controls (fold change (FC) = 9.12 ± 0.56; p < 0.05), while NT-4 transcriptional activity was decreased in the test samples compared with the controls (FC = 0.33 ± 0.07; p < 0.05). However, at the protein level, the concentrations of NT-3 (134 ± 5.78 pg/mL vs. 6.78 ± 1.17 pg/mL; p < 0.05) and NT-4 (316.77 ± 8.19 pg/mL vs. 76.92 ± 4.82 pg/mL; p < 0.05) were significantly higher in the test samples compared with the control samples. Nevertheless, the concentration of both proteins did not statistically significantly change depending on the advancement of degenerative changes and the pain intensity (p > 0.05). In addition, higher levels of NT-3 and NT-4 were noted in IVD samples from patients who consumed alcohol, smoked tobacco, were overweight/obese, or had comorbid diabetes compared with patients without these risk factors (p < 0.05). Our analysis confirmed that differences in the degenerative process of IVD, energy metabolism, and lifestyle are related to changes in the concentration profiles of NT-3 and NT-4.

Lumbar Disc Degeneration Is Linked to Dorsal Subcutaneous Fat Thickness at the L1-L2 Intervertebral Disc Level Measured by MRI

BACKGROUND

Obese individuals have a higher risk of degenerative disc disease (DDD). Currently, body mass index is not sensitive enough to differentiate between muscle and fat distribution, and obesity-related health issues are linked to the way body fat is distributed. Therefore, this study aims to investigate the association between the dorsal subcutaneous fat thickness (DSFT) of the lumbar spine, an alternative measurement tool of body fat distribution, and DDD.

METHODS

A total of 301 patients with DDD and 123 participants without the disease were recruited. Using length functions of magnetic resonance imaging (MRI) console, the DSFT of L1 to S1 intervertebral disc levels was measured in mid-sagittal spin-echo T2 weighted image. The Mann-Whitney U test and Chi-squared test (X2) were utilized to examine any variations between the case and control groups. Logistic regression models were built to explore the association of the DSFT with DDD.

RESULTS

The logistical regression model showed a positive association between DDD and DSFT [OR: 1.30, 95% CI: 1.02-1.64, p = 0.03]. In the stratified logistic regression analysis, a positive association was found between DDD and DSFT among younger participants and females [OR young: 1.48; 95% CI (1.02-2.20); p = 0.04-OR female: 1.37; 95% CI (1-1.88); p = 0.05].

CONCLUSIONS

Younger females with thicker DSFT at the L1-L2 level are more likely to develop DDD. This suggests that increased DSFT may be a contributing factor to DDD.

Effect of Glycemic Disorders and Habits on the Concentration of Selected Neurotrophic Factors in Patients with Lumbosacral Intervertebral Disc Degeneration

BACKGROUND

Unhealthy habits, such as overeating processed and high-calorie foods, alcohol abuse, and smoking, negatively impact human health. It has been suggested that the inflammatory process and the resulting growth of nerve fibers within the intervertebral disc (IVD) fissures is the main reason for the pain accompanying IVD degeneration (IVDD).

OBJECTIVES

The aim of this study was to determine whether smoking, alcohol consumption, overweight/obesity, or diabetes comorbidity contribute to the development of IVDD and how the aforementioned factors affect the levels of brain-derived neurotrophic factor (BDNF), glial cell-derived neurotrophic factor (GDNF), and growth associated protein 43 (GAP-43) in the study and control groups (intervertebral discs, IVDs from cadavers, and serum samples from voluntary blood donors).

METHODS

The study group comprised 113 patients diagnosed with IVDD who qualified for microdiscectomy. Two control groups (I and II) were used in this study. The first included 81 IVDs obtained from Caucasian human cadavers. Control group II, on the other hand, included serum samples obtained from 113 voluntary blood donors. The expression profiles of BDNF, GDNF, and GAP-43 were determined by enzyme-linked immunosorbent assay (ELISA).

RESULTS

Our statistical analysis confirmed that patients who were overweight/obese, smoked tobacco, consumed alcohol, or had diabetes had a higher risk of IVDD (OR > 1). Statistical analysis showed that BDNF, GAP-43, and GDNF concentrations were significantly higher in the IVDs and serum samples obtained from the study group compared to the control group (p < 0.05). In addition, higher levels of BDNF, GDNF, and GAP-43 were noted in IVDD patients who consumed alcohol, smoked tobacco, were overweight/obese, or had comorbid diabetes compared to patients without these risk factors (p < 0.05).

CONCLUSION

We showed that changes in energy metabolism, habits, and lifestyle, as well as the degenerative process of IVD in the lumbosacral spine contribute to changing the concentration profile of the analyzed neurotrophic factors.

Potential blood markers as screening tools for subjects with low back pain: an age- and gender-matched cross-sectional analysis

BACKGROUND

Mechanical and inflammatory factors were suggested as the causes of spine degeneration and low back pain (LBP). Previous studies partly reported the association of LBP with inflammation. However, none of them compared patients with LBP and asymptomatic subjects in terms of complete blood count and inflammatory markers in detail. We aimed to analyze the association of serum white blood cell (WBC) count, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) with chronic LBP by comparing the patients with chronic LBP and age- and gender-matched asymptomatic subjects.

METHODS

Lumbar intervertebral disc degeneration and vertebral end-plates were evaluated using Pfirrmann grading and Modic classification on lumbar spine magnetic resonance images, respectively. Serum WBC counts, CRP levels, and ESRs were recorded from chart reviews.

RESULTS

We included 147 patients with chronic LBP and 101 asymptomatic subjects. Patients with chronic LBP had significantly higher serum neutrophil, monocyte, and basophil counts, higher neutrophil-to-lymphocyte ratio, higher ESR, and lower serum CRP levels compared to the asymptomatic subjects. Serum monocyte and basophil cell counts and ESR were the most remarkable predictive factors for chronic LBP, severe IVDD, and Modic changes. Higher serum monocyte and basophil cell counts and higher serum ESR above cut-off values of 0.42 × 103/μL, 0.025 × 103/μL, and 3.5 mm/hour could be used as screening tools for subjects with persistent LBP in primary care.

DISCUSSION

Higher serum monocyte and basophil counts and serum ESR above new cut-off values should highlight the need to obtain early spinal imaging to prevent chronicity in patients with LBP.

Low Back Pain in Resident Doctors with Standardized Training in China: A Cross-Sectional Study

Background

Low back pain (LBP) is a prevalent occupational disease with high morbidity among healthcare workers. Since the implementation of standardized residency training in China in 2015, the training intensity has significantly increased, which may lead to a higher incidence of LBP. However, epidemiological studies on LBP among resident doctors with standardized training remain scarce.

Objective

To investigate the prevalence and associated factors of LBP among resident doctors with standardized training in a tertiary hospital in China.

Methods

A cross-sectional study was conducted using self-administered questionnaires to collect information on demographics, lifestyle factors, work-related factors, and LBP from 345 resident doctors. Descriptive statistics were used to analyze the prevalence of LBP. Logistic regression analysis was performed to identify factors associated with LBP.

Results

Among 345 participants, the 1-year prevalence of LBP was 75.9%. Multivariable analysis revealed that physical exercise, weekly working hours, and prolonged sitting were independent risk factors for LBP.

Conclusion

The prevalence of LBP among resident doctors was high. Promoting physical exercise, controlling working hours, and improving sitting posture may help prevent LBP. The study was limited by its cross-sectional design and self-reported data. Future studies should use longitudinal designs, objective measures, and larger and more representative samples to further explore the epidemiology and etiology of LBP among resident doctors with standardized training.

Complication Pattern After Percutaneous Cement Discoplasty: Identification of Factors Influencing Reoperation and Length of Hospital Stay

OBJECTIVE

Percutaneous cement discoplasty (PCD) was introduced to treat symptomatic vertical instability of the lumbar spine in a minimally invasive way. The aim of the present study was to analyze the complication pattern after PCD and to identify factors that predict the chance of cement leakage, reoperation, and length of hospital stay (LOS).

METHODS

patients were treated with PCD within the study period. Clinical features and complications were analyzed by applying descriptive statistics, whereas perioperative factors predictive of cement leakage, reoperation, and LOS were identified by regression models.

RESULTS

Cement leakage rate was 30.4% in the total cohort; however, only fifth of them were symptomatic. Cement leakage itself did not have a significant influence on clinical outcome. Other complications and nonsurgical adverse events were registered only in 2.0% of cases. Age, subcutaneous fat tissue thickness, low viscosity cement, lower level of surgeon's experience and the number of operated levels were identified as risk factors of cement leakage (P < 0.01; c-index = 0.836). Type of procedure, Charlson comorbidity score, reoperation, and nonsurgical adverse events significantly increased the LOS (P < 0.01). Cement leakage, early surgical practice, and increased subcutaneous fat tissue thickness were risk factors for reoperation (P < 0.01; c-index = 0.72).

CONCLUSIONS

PCD is a relatively safe and effective procedure for treating spinal instability caused by advanced-stage disc degeneration characterized by vacuum phenomenon. Cement leakage is not uncommon but is only a radiologic complication without clinical consequences in most cases. On the other hand, it can increase the LOS and is a significant risk factor for reoperation.

A novel radiological index for the evaluation of cervical posterior subcutaneous fat tissue thickness and cervical spine degeneration: A retrospective study

Obesity is an important risk factor linked to the incidence of both neck pain (NP) and intervertebral disc degeneration (IVDD). Subcutaneous fat tissue thickness (SFTT) has been proposed as a more effective biomarker than body mass index (BMI) when gauging body fat levels. This study was thus designed to explore the optimal SFTT cutoff value for differentiating between NP patients and asymptomatic individuals by using the subcutaneous fat index (SFI). Magnetic resonance imaging (MRI) records from NP patients and asymptomatic controls were compared to evaluate IVDD, the fatty infiltration of the paravertebral muscles, and Modic changes. Cervical SFTT was also assessed at multiple levels. SFTT at the C3 level was found to be significantly associated with NP, with respective optimal cutoff values of 9.64 mm and 8.21 mm for females and males. Females in this study cohort more frequently exhibited spine deterioration with an SFI > 9.64 mm as compared to males with an SFI > 8.21 mm. Cervical SFTT is strongly correlated with the degree of disc degeneration. IVDD, Modic changes, and fatty infiltration in the paravertebral muscles were all more prevalent among both males and females exhibiting SFTT at the C3 level that was above the defined cutoff value.

Are serum thyroid hormone, parathormone, calcium, and vitamin D levels associated with lumbar spine degeneration? A cross-sectional observational clinical study

PURPOSE

Low back pain (LBP) impairs the quality of life and rises healthcare costs. The association of spine degeneration and LBP with metabolic disorders have been reported, previously. However, metabolic processes related with spine degeneration remained unclear. We aimed to analyze whether serum thyroid hormones, parathormone, calcium, and vitamin D levels were associated with lumbar intervertebral disc degeneration (IVDD), Modic changes, and fatty infiltration in the paraspinal muscles.

METHODS

We cross-sectionally analyzed a retrospective database. Patients who visited internal medicine outpatient clinics with suspect of endocrine disorders and chronic LBP were searched. Patients with biochemistry results within 1 week before lumbar spine magnetic resonance imaging (MRI) were included. Age- and gender-matched cohorts were made-up and analyzed.

RESULTS

Patients with higher serum free thyroxine levels were more likely to have severe IVDD. They were also more likely to have fattier multifidus and erector spinae at upper lumbar levels, less fatty psoas and less Modic changes at lower lumbar levels. Higher PTH levels were observed in patients with severe IVDD at L4-L5 level. Patients with lower serum vitamin D and calcium levels had more Modic changes and fattier paraspinal muscles at upper lumbar levels.

CONCLUSION

Serum hormone, vitamin D, and calcium levels were associated with not only IVDD and Modic changes but also with fatty infiltration in the paraspinal muscles, mainly at upper lumbar levels in patients with symptomatic backache presenting to a tertiary care center. Complex inflammatory, metabolic, and mechanical factors present in the backstage of spine degeneration.

Prediction of Pedicle Screw Loosening Using an MRI-Based Vertebral Bone Quality Score in Patients with Lumbar Degenerative Disease

OBJECTIVE

To explore a new magnetic resonance imaging (MRI)-based bone quality assessment method for predicting pedicle screw loosening in the lumbar spine.

METHODS

We reviewed 174 patients aged ≥50 years who were treated for lumbar degenerative diseases using posterior lumbar interbody fusion. All patients were followed-up for ≥12 months. Based on the presence of radiolucent areas on follow-up MRI images, the patients were divided into loosening and nonloosening groups. The vertebral bone quality (VBQ) score was calculated using T1-weighted MRI images. Demographic data, health history, and radiological parameters were also recorded and compared between the 2 groups. Logistic regression analysis was used to predict the independent risk factors affecting screw loosening.

RESULTS

Screw loosening occurred in 29.88% (52/174) of patients. A total of 83 screws (9.18%, 83/904) were loosened. There were differences in the age, fixation length, fixation at S1, preoperative and postoperative PI-LL, PT, preoperative LL, lowest bone mineral density (BMD), and VBQ scores (P < 0.05) between the nonloosening and loosening groups. In the logistic regression, the VBQ score (OR = 1.02 per point; 95% CI: 1.01-1.03; P < 0.001) was identified as an independent factor influencing screw loosening.

CONCLUSIONS

As an independent risk factor for screw loosening after lumbar spine fusion, the VBQ score provides a new noninvasive protocol for assessing bone quality during surgical planning.

The morphological characteristics of paraspinal muscles in young patients with unilateral neurological symptoms of lumbar disc herniation

Objective

The objective of this study was to explore the morphological characteristics of paraspinal muscles in young patients with unilateral neurological symptoms of lumbar disc herniation.

Methods

This study retrospectively analyzed young patients aged 18–40 years who were hospitalized for lumbar disc herniation in our hospital from June 2017 to June 2020. Data on sex, age, body mass index (BMI), subcutaneous fat tissue thickness (SFTT) at the L1-L2 level, duration of symptoms, degree of lumbar disc herniation, visual analog scale (VAS) for the lower back, Mo-fi-disc score, relative cross-sectional area (RCAS) of the paravertebral muscles (psoas major [PM], multifidus [MF], and erector spinae [ES]), and degree of fat infiltration (DFF) of the paravertebral muscles were collected. The VAS was used to evaluate the intensity of low back pain. Patients with VAS-back >4 points were defined as the low back pain group, and patients with ≤4 points were defined as the control group. The demographic characteristics, as well as the bilateral and ipsilateral paravertebral muscles, of the two groups were compared and analyzed.

Result

A total of 129 patients were included in this study (52 patients in the LBP group and 77 patients in the control group). There were no significant differences in sex, BMI, or Pfirrmann grade of lumbar disc herniation between the two groups (P > 0.05). The age of the LBP group (33.58 ± 2.98 years) was greater than that of the control group (24.13 ± 2.15 years) (P = 0.002), and the SFTT at the L1-L2 level (13.5 ± 7.14 mm) was higher than that of the control group (7.75 ± 6.31 mm) (P < 0.05). Moreover, the duration of symptoms (9.15 ± 0.31 months) was longer than that of the control group (3.72 ± 0.48 months) (P < 0.05), and the Mo-fi-disc score (8.41 ± 3.16) was higher than that of the control group (5.53 ± 2.85) (P < 0.05). At L3/4 and L5/S1, there was no significant difference in the RCSA and DFF of the bilateral and ipsilateral paraspinal muscles between the LBP group and the control group. At L4/5, there was no significant difference in the RCSA and DFF of the paraspinal muscles on either side in the LBP group (P > 0.05). In the control group, the RCSA of the MF muscle on the diseased side was smaller than that on the normal side (P < 0.05), and the DFF of the MF muscle on the diseased side was larger than that on the normal side (P < 0.05). In addition, there was no significant difference in the ES and PM muscles on both sides (P > 0.05). At L4/5, the RCSA of the MF muscle on the normal side was significantly smaller in the LBP group than in the control group (P < 0.05), and the DFF of the MF muscle on the normal side was significantly larger in the LBP group than in the control group (P < 0.05). There was no significant difference in the ES and PM muscles on the same side between the two groups (P > 0.05).

Conclusion

In young patients with unilateral neurological symptoms of lumbar disc herniation, symmetrical atrophy of the bilateral MF muscle is more prone to causing low back pain. Older age, higher SFTT at the L1-L2 levels, longer symptom duration, higher Mo-fi-di score, and greater muscle atrophy on the normal side of the MF increased the incidence of low back pain in young patients with unilateral lumbar disc herniation.

Small Preoperative Dural Sac Cross-Sectional Area and Anteriorly Placed Fusion Cages Are Risk Factors for Indirect Decompression Failure after Oblique Lateral Interbody Fusion

OBJECTIVE

1) To investigate if implant-related factors such as cage size and cage position are associated with radiologic improvement after indirect decompression with oblique lateral interbody fusion (OLIF). 2) To investigate the risk factors associated with indirect decompression failure (IDF) at the surgical levels after OLIF.

METHODS

From February 2015 to December 2019, 92 consecutive patients (188 levels) with lumbar spinal stenosis who underwent indirect decompression via OLIF with or without posterior instrumentation were studied retrospectively. Radiographic variables were measured preoperatively and postoperatively. The radiographic results were compared for cages with different heights and positions. IDF was defined as revision surgery within 6 months or persistent compressive symptoms 6 months after surgery.

RESULTS

Postoperative improvements were observed in all measured radiographic parameters except for segmental lordosis. Taller cages were associated with more shrinkage of the bulging disc and greater increase in dural sac diameter. Cages placed posteriorly showed larger postoperative subarticular diameters. Twelve patients (16 levels) had IDF. Multivariate logistic regression showed that after adjusting for age, sex, and body mass index, smaller preoperative dural sac cross-sectional area and anterior positioning of cages were both independent risk factors for IDF.

CONCLUSIONS

OLIF is an effective procedure for indirect decompression. To avoid reoperation for lumbar spinal stenosis, surgeons should aim to place the center of the cage at the posterior half of the lower endplate. Surgical levels with a preoperative dural sac cross-sectional area <44 mm2 may not be suitable for indirect decompression.

Comparison of multifidus degeneration between scoliosis and lumbar disc herniation

Objective

To assess and compare the pathological and radiological outcomes of multifidus degeneration in scoliosis and lumbar disc herniation patients.

Methods

We performed a retrospective review on 24 patients with scoliosis and 26 patients with lumbar disc herniation (LDH) in the Third Hospital of Hebei Medical University from January 2017 to March2021. The patients were divided into scoliosis group and LDH group according to the treatment. The MRI fatty infiltration rate (FIR) of multifidus and strength of back muscle were calculated to evaluate muscle condition. Multifidus biopsy samples were obtained during surgery in the affected side at L4 or L5 segment in LDH group and on the concavity side of apical vertebrae in scoliosis group. The biopsy fatty infiltration degree (FID) and FIR in two groups, the FIR of affected and unaffected side in LDH group, and the FIR of concavity and convexity side in scoliosis group were compared. The correlation between concavity-convexity FIR difference and cobb angle in scoliosis group, back muscle strength and FIR in LDH group, FID and FIR in both groups was calculated respectively.

Results

The FIR was higher in scoliosis group than in LDH group, higher in concavity side than convexity side in scoliosis group (both P < 0.05). The FID was higher in scoliosis group than in LDH group (P < 0.05). No significant difference was found between affected and unaffected side in LDH group (P > 0.05). There was a positive correlation between concavity-convexity FIR difference and cobb angle, FIR and FID (both P < 0.01). There was a negative correlation between back muscle strength and FIR (P < 0.01). The biopsy staining results showed that both two groups were found the existence of rimmed vacuoles, nuclear aggregation, and abnormal enzyme activity, indicating that the scoliosis and LDH may be associated with myogenic diseases.

Conclusion

The scoliosis patients showed more serious fatty infiltration than LDH patients and rare pathological findings were found in both diseases.

Subcutaneous fat index: a reliable tool for lumbar spine studies

OBJECTIVES

Obesity has been proposed as a risk factor for low back pain (LBP), and the body mass index (BMI) has been used for obesity; however, a more reliable tool is required to assess obesity-related health issues. A recent study depicted the subcutaneous fat tissue thickness (SFTT) at the L1-L2 level as superior to BMI in predicting LBP and spine degeneration. However, the study failed to answer the following questions: (1) What was the cutoff value for the SFTT to predict LBP and spine degeneration? (2) Could this new index be adjusted according to gender? (3) Could this new index predict fatty infiltration in the paraspinal muscles, severe intervertebral disk degeneration (IVDD), and Modic changes in the lumbar spine? Therefore, the current study aimed to answer these questions by developing and validating a new anthropometric index-the subcutaneous fat index (SFI).

METHODS

This study retrospectively reviewed the magnetic resonance imaging database of patients with LBP and compared them with asymptomatic volunteers.

RESULTS

Appropriate cutoff values for females and males were 8.45 mm and 9.4 mm, respectively. Females and males with the SFI of > 8.45 mm and > 9.4 mm, respectively, had significantly higher rates of spine degeneration.

CONCLUSION

The SFI reliably distinguished patients with LBP from the asymptomatic subjects and could reliably distinguish patients with severe IVDD/Modic changes at the lower lumbar levels and those with moderate-to-severe fat-infiltrated paraspinal muscles at all lumbar levels with reliable cutoff values for males and females.

KEY POINTS

• The subcutaneous fat tissue thickness at L1-L2 level (subcutaneous fat index [SFI]) was superior to BMI in predicting LBP and spine degeneration. However, a reliable cutoff value has not been previously defined. • The subcutaneous fat index had reliable cutoff values of 8.45 mm and 9.4 mm for females and males, respectively. • Females with an SFI of > 8.45 mm and males with > 9.4 mm had significantly higher rates of severe IVDD, Modic changes, and fatty infiltration in their paraspinal muscles.

Advances in research on fat infiltration and lumbar intervertebral disc degeneration

Low back pain (LBP) is a disabling condition with no available cure, severely affecting patients' quality of life. Intervertebral disc degeneration (IVDD) is the leading cause of chronic low back pain (CLBP). IVDD is a common and recurrent condition in spine surgery. Disc degeneration is closely associated with intervertebral disc inflammation. The intervertebral disc is an avascular tissue in the human body. Transitioning from hematopoietic bone marrow to bone marrow fat may initiate an inflammatory response as we age, resulting in bone marrow lesions in vertebrae. In addition, the development of LBP is closely associated with spinal stability imbalance. An excellent functional state of paraspinal muscles (PSMs) plays a vital role in maintaining spinal stability. Studies have shown that the diminished function of PSMs is mainly associated with increased fat content, but whether the fat content of PSMs is related to the degree of disc degeneration is still under study. Given the vital role of PSMs lesions in CLBP, it is crucial to elucidate the interaction between PSMs changes and CLBP. Therefore, this article reviews the advances in the relationship and the underlying mechanisms between IVDD and PSMs fatty infiltration in patients with CLBP.