Association between ossification of the longitudinal ligament of the cervical spine and arteriosclerosis in the carotid artery

Factors Associated With Repeat Surgery in Cervical Ossification of the Posterior Longitudinal Ligaments: Minimum 8-year Follow-up Study

STUDY DESIGN

Single-center retrospective study.

OBJECTIVE

The objective of this study is to identify the factors leading to repeat surgery in patients with cervical ossification of the longitudinal ligament (OPLL) during a minimal 8-year follow-up after the initial surgery.

SUMMARY OF BACKGROUND DATA

The long-term effects of cervical OPLL are well known, but it's not always clear how many patients need to have surgery again because their neurological symptoms get worse.

METHODS

This study is included 117 patients who underwent surgery for cervical OPLL and had a follow-up of at least 8 years. OPLL type, surgical extent, surgical method, and sagittal radiological parameters were measured, and OPLL characteristics were analyzed.

RESULTS

The average age of patients at the time of surgery was 53.2 years, with a male-to-female ratio of 78:39. The median follow-up duration was 122 months (96-170 mo). Out of the total, 20 cases (17.1%) necessitated repeat surgery, among which 8 cases required surgery at the same site as the initial operation. The highest rate of repeat surgery was observed in patients who underwent total laminectomy without fusion (TL), where 6 out of 21 patients (29%) needed a second surgery, and 5 of these (23%) involved the same surgical site. Patients who underwent repeat surgery at the same site exhibited a greater range of motion (ROM) one year postsurgery (16.4 ± 8.5° vs. 23.1 ± 12.7°, P =0.041). In addition, the ROM at 1 year was higher in patients who underwent TL compared with those who had laminoplasty. Furthermore, the recurrence rate for hill-shape OPLL was higher at 30.8% compared to 10% for plateau-shape OPLL ( P = 0.05).

CONCLUSION

Larger cervical ROM 1 year after surgery is related to repeat surgery at the same level as previous surgery, especially in laminectomy without fusion surgery.

Patients with a large ossification of the posterior longitudinal ligament have a higher incidence of arteriosclerosis in the carotid artery

PURPOSE

This study aimed to investigate the impact of the severity of cervical ossification of the posterior longitudinal ligament (OPLL) on the incidence of arteriosclerosis in the carotid artery.

METHODS

Patients with OPLL-induced cervical myelopathy were prospectively enrolled. The study involved analyzing patient characteristics, blood samples, computed tomography scans of the spine, and intima-media thickness (IMT) measurements of the common carotid artery. Patients were divided into two groups based on the size of the cervical OPLL to compare demographic data, comorbidities, and the presence of thickening of the carotid intima-media (max IMT ≥ 1.1 mm).

RESULTS

The study included 96 patients (mean age: 63.5 years; mean body mass index: 26.9 kg/m2; 71.8% male; 35.4% with diabetes mellitus). The mean maximum anteroposterior (AP) diameter of the OPLL was 4.9 mm, with a mean occupancy ratio of 43%. The mean maximum IMT was 1.23 mm. Arteriosclerosis of the carotid artery was diagnosed in 62.5% of the patients. On comparing the two groups based on OPLL size, the group with larger OPLL (≥ 5 mm) had a higher BMI and a greater prevalence of carotid intima-media thickening. This significant difference in the prevalence of carotid intima-media thickening persisted even after adjusting for patient backgrounds using propensity score matching.

CONCLUSIONS

Patients with a larger cervical OPLL showed a higher frequency of intima-media thickening in the carotid artery.

Predictors of the Need for Surgery in Cervical Ossification of the Posterior Longitudinal Ligament: A Retrospective Cohort Longitudinal Study Using a Claims-based Database

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

The aim of this study was to determine predictors associated with the needfor cervical ossification of the posterior longitudinal ligament (cOPLL) surgery amongindividuals with cOPLL.

SUMMARY OF BACKGROUND DATA

cOPLL is a spinal disorder caused by ectopic ossification of the posterior longitudinal ligament. However, factors associated with a higher rate of surgery to treat the neurological symptoms of cOPLL are poorly understood.

MATERIALS AND METHODS

This retrospective population-based cohort study using a commercial administrative claims database from JMDC Inc. (Tokyo, Japan) enrolled patients newly diagnosed with cOPLL from April 2005 to October 2020 and followed to April 2021. A total of 1506 cOPLL patients aged 18 years or older with no history of cervical spine surgery and with a record of metabolic profiles obtained at general health checkups were included. Cox proportional hazards regression models identified patient characteristics and comorbidities associated with cOPLL surgery.

RESULTS

Of 1506 patients with cOPLL with a median of 1.8 years of follow-up after initial cOPLL diagnosis, 439 (29.2%) received cOPLL surgery. The 1-year cumulative incidence (95% CI) was 26.0% (23.7-28.2). In multivariable Cox proportional regression analysis, male (hazard ratio: 1.68; 95% CI: 1.26-2.24; P < 0.001) and obesity (body mass index: ≥25) (hazard ratio: 1.45; 95% CI: 1.10-1.89; P = 0.007) were associated with an increased risk of cOPLL surgery.

CONCLUSIONS

In this large claims-based study of adults newly diagnosed with cOPLL, males and obesity were associated with a higher risk of cOPLL surgery. These findings may help clinicians to predict the future course of cOPLL in patients, although further research is needed to elucidate the biological role of these progression-associated factors.

Evaluation of bone strength using finite-element analysis in patients with ossification of the posterior longitudinal ligament

BACKGROUND CONTEXT

Patients with ossification of the posterior longitudinal ligament (OPLL) are often reported to have increased bone mineral density (BMD). The bone strength of the proximal femur measured by quantitative computed tomography-based finite element analysis (QCT/FEA) is reportedly comparable between healthy subjects with and without OPLL. However, the bone strength in symptomatic OPLL patients remains unknown.

PURPOSE

To investigate bone strength measured by QCT/FEA in symptomatic patients with OPLL.

STUDY DESIGN/SETTING

A single-center prospective observational study.

PATIENT SAMPLE

A total of 157 patients with cervical or thoracic compressive myelopathy were included in the study.

OUTCOME MEASURES

We analyzed patients' characteristics, Japanese Orthopedic Association (JOA) score, serum laboratory tests including calcium (Ca), inorganic phosphate (Pi), and bone turnover markers, BMD of the proximal femur and lumbar spine measured using dual-energy X-ray absorptiometry, and predicted bone strength (PBS) of the proximal femur and lumbar spine measured using QCT/FEA.

METHODS

Eligible patients were divided into the non-OPLL and OPLL groups. We compared the patients' characteristics, JOA scores, laboratory data, BMD, and PBS of the proximal femur and lumbar spine between the non-OPLL and OPLL groups among total, male, and female patients by performing Fisher's exact test for categorical variables and the unpaired t test for continuous variables. Then, we used the inverse probability weighted logistic regression model after calculating propensity scores to compare the bone metabolism-associated markers, BMD, and PBS measurements between the groups.

RESULTS

Among the eligible 157 patients, 68 were in the non-OPLL group and 89 were in the OPLL group. Compared with the non-OPLL group, the OPLL group had a significantly younger age and higher BMI in the total, male, and female patients. The JOA scores in the total and female patients were significantly higher in the OPLL group than in the non-OPLL group. The OPLL group showed significantly lower Ca levels in the female patients and significantly lower Pi levels in the total or male patients compared with the non-OPLL group in the inverse probability weighting method. The BMD of the proximal femur and lumbar spine and the PBS of the proximal femur were significantly higher in the OPLL group than in the non-OPLL group. There were no significant differences in the PBS and BMD between the male subgroups. However, the BMD and PBS of the proximal femur and lumbar spine were significantly higher in the OPLL females than in the non-OPLL females.

CONCLUSIONS

Hyperostosis of the posterior longitudinal ligament in OPLL was associated with higher bone strength by QCT/FEA, especially in female OPLL patients.

High Body Mass Index Is Associated with an Increased Risk of the Onset and Severity of Ossification of Spinal Ligaments

Background

Ossification of the posterior longitudinal ligament (OPLL) and that of ligamentum flavum (OLF) are the main types of the ossification of spinal ligaments (OSL) that cause the thoracic myelopathy. Although several studies have investigated the relationship of body mass index (BMI) with the onset or severity of OSL, it remains unverified due to the contradictory results of existing evidence. A systematic review and meta-analysis were performed in this work to determine the relationship of BMI with the onset and severity of OSL.

Methods

PubMed, EMBASE, Web of Science, and Cochrane Library were comprehensively searched online for relevant studies focusing on the relationship of BMI with the onset or severity of the OSL. The difference in BMI of OSL (or severe OSL group) and non-OSL (or nonsevere OSL group) groups was evaluated using the mean difference (MD) with a corresponding 95% confidence interval (CI).

Results

Fifteen studies were included in this systematic review and meta-analysis. The BMI of the OSL group was significantly higher than that of the non-OSL group (MD = 1.70 kg/m², 95% CI = 1.02–2.39 kg/m², and P < 0.01). Similar results were observed in the subgroup analysis of female (P < 0.01), OPLL (P < 0.01), and OLF (P < 0.01) populations. Three studies reported a significant association of BMI with the ossification index of OSL and the standardized regression coefficient ranging from 0.11 to 0.43 (P < 0.05). Moreover, a significantly higher BMI was observed in the severe OSL group compared with that in the nonsevere OSL group (MD = 3.09, 95% CI, 0.22–5.97 kg/m², and P = 0.04).

Conclusion

The significant association of high BMI with the onset and severity of OSL may provide new evidence and insights into the mechanism research and management of OSL.

Clinical Risk Factors for Thoracic Ossification of the Ligamentum Flavum: A Cross-Sectional Study Based on Spinal Thoracic Three-Dimensional Computerized Tomography

Background

Inconsistent results of the clinical risk factors associated with thoracic ossification of the ligamentum flavum (TOLF) have been reported in limited previous studies.

Purpose

This retrospective study aimed to investigate the potential risk factors for TOLF by a retrospective cross-sectional study, which may provide valuable experience for further clinical and pathophysiological research.

Methods

A total of 2247 asymptomatic participants, who underwent spinal thoracic three-dimensional computerized tomography (3D-CT) scans at our institution from January 2016 to December 2019, were enrolled in this study according to the screening criteria. Demographic information such as age, sex, height, weight, body mass index (BMI), smoking and drinking history, diastolic blood pressure (DBP), systolic blood pressure (SBP), and pulse pressure (PP) were recorded. Laboratory results included serum low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), total cholesterol (TC), triglyceride (TG), uric acid (UA), creatinine (Cr), calcium, and phosphorus. Participants were divided into TOLF group and non-TOLF group in accordance with the thoracic 3D-CT manifestation.

Results

TOLF was observed in 153 (6.81%) asymptomatic participants. Comparison of demographic data and laboratory examinations between the two groups showed that participants in the TOLF group were older, had a higher BMI, as well as higher levels of DBP. In addition, there was no significant difference in sex, drinking, tobacco use, SBP, TC, TG, PP, and levels of LDL-C, HDL-C, sUA, sCr, calcium, and phosphorus between the two groups. Furthermore, dichotomous logistic regression analyses revealed that age (OR = 1.018, p = 0.041) and BMI (OR = 1.090, p < 0.001) were risk factors for TOLF.

Conclusion

Our study reveals that age and BMI are clinical risk factors for the development of TOLF, while age cannot be identified as an independent risk factor for female in subgroup analysis.

Physical Activity Related to Body Muscle Mass Index and Stiffness Index in 7-to-10-Year-Old Girls

The relationship between moderate-to-vigorous physical activity (MVPA) performance time and body muscle mass and stiffness index in pre-puberty school-aged girls has not been fully elucidated. The effect of sexual maturity on bone mass is more pronounced in girls. This study aimed to clarify the relationship between MVPA performance time and the above-mentioned factors. This was a prospective, population-based cohort study of 111 girls aged 7–10 years. Data were collected via medical examination, clinical measurements, and questionnaires. Spearman’s ρ analysis was used to determine the association between skeletal muscle mass index (SMI) and stiffness index, muscle strength, and MVPA performance time. Participants who met the recommended MVPA level accounted for only 24.3% (n = 27) of all participating girls (n = 111). The following factors were significantly positively correlated with MVPA level at spearman’s ρ analysis: SMI (r = 0.303, p = 0.001), stiffness index (r = 0.229, p = 0.015), grip strength (r = 0.283, p = 0.003), back muscle strength (r = 0.197, p = 0.038), and standing long jump distance (r = 0.288, p = 0.002). Multiple regression analysis’s results revealed that SMI (β = 0.237; p = 0.024) was associated with MVPA performance time. These results can help school-aged girls to pay adequate attention to having healthy physical activity habits to prevent the decline of skeletal muscle mass, stiffness index, and body muscle strength.

Biomarker Research Approach To The Pathogenesis Of Ossification Of The Spinal Ligament: A Review

The ossification of the spinal ligaments (OSL) is characterized by ectopic new bone formation in the spinal ligament. However, the etiology of OSL has not yet been fully elucidated. This review paper summarizes the contents of previous reviews, introduces recent advances in the study of OSL and discusses future perspectives. A review of the literature that investigated the biomarkers involved in OPLL was published in 2019. The review cited 11 reports in which a calcium phosphate metabolism marker, bone turnover markers, sclerostin, dickkopf-1, secreted frizzled-related protein-1, fibroblast growth factor-23, fibronectin, menatetrenone, leptin, pentosidine, and hypersensitive C-reactive protein were examined as markers. Data published in 2021 noted that non-coding RNAs might be useful biomarkers for OSL. In addition, triglycerides, uric acid, gene expression levels of interleukin-17 receptor C, chemokine (C-X-C motif) ligand 7 (CXCL7) in the serum reportedly are biomarkers of OSL. However, several issues have been raised in previous studies. Therefore, biomarkers have yet to be conclusively investigated. Research using biomarkers is very important in clarifying pathomechanisms. Results for studies using biomarkers might also be useful for the treatment of patients with OSL in the near future.

Factors Related to Locomotive Syndrome in School-Aged Children in Okazaki: A Cross-Sectional Study

The relationship of locomotive syndrome with other physical characteristics and lifestyle habits in children has not been fully elucidated. The aim of this study was to assess the prevalence of children's locomotive syndrome, and to determine its relationship with the above-mentioned factors. This was a cross-sectional study of 285 elementary school children who volunteered to participate in a medical checkup for physical function. Data was collected via medical examination, clinical measurements, and questionnaires. A multivariable logistic regression model was used to determine the relationship (odds ratios; ORs) of participants' characteristics, physical functions, and other outcomes determined by questionnaire on locomotive syndrome. The following factors were related to locomotive syndrome: older age (OR = 1.421, 95% confidence interval [CI] [1.039, 1.945]), male sex (OR = 4.011, 95% CI [2.189, 7.347]), and more time spent watching television per day (OR = 1.281, 95% CI [1.001, 1.640]). These results may assist in the encouragement of children to perform appropriate physical activities and avoid unhealthy lifestyle habits, reducing the occurrence of locomotive syndrome.