Effect of compression fracture on trabecular bone score at lumbar spine

Clinical Use of Trabecular Bone Score: The 2023 ISCD Official Positions

Osteoporosis can currently be diagnosed by applying the WHO classification to bone mineral density (BMD) assessed by dual-energy x-ray absorptiometry (DXA). However, skeletal factors other than BMD contribute to bone strength and fracture risk. Lumbar spine TBS, a grey-level texture measure which is derived from DXA images has been extensively studied, enhances fracture prediction independent of BMD and can be used to adjust fracture probability from FRAX® to improve risk stratification. The purpose of this International Society for Clinical Densitometry task force was to review the existing evidence and develop recommendations to assist clinicians regarding when and how to perform, report and utilize TBS. Our review concluded that TBS is most likely to alter clinical management in patients aged ≥ 40 years who are close to the pharmacologic intervention threshold by FRAX. The TBS value from L1-L4 vertebral levels, without vertebral exclusions, should be used to calculate adjusted FRAX probabilities. L1-L4 vertebral levels can be used in the presence of degenerative changes and lumbar compression fractures. It is recommended not to report TBS if extreme structural or pathological artifacts are present. Monitoring and reporting TBS change is unlikely to be helpful with the current version of the TBS algorithm. The next version of TBS software will include an adjustment based upon directly measured tissue thickness. This is expected to improve performance and address some of the technical factors that affect the current algorithm which may require modifications to these Official Positions as experience is acquired with this new algorithm.

Adjusting Trabecular Bone Score (TBS) for Level-Specific Differences Reduces FRAX®-Based Treatment Reclassification in Patients with Vertebral Exclusions: The Manitoba BMD Registry

Trabecular bone score (TBS) is a FRAX®-independent risk factor for fracture prediction. TBS values increase from cranial to caudal, with the following mean differences between TBSL1-L4 and individual lumbar vertebrae: L1 -0.093, L2 -0.008, L3 +0.055 and L4 +0.046. Excluding vertebral levels can affect FRAX-based treatment recommendations close to the intervention threshold. We examined the effect of adjusting for level-specific TBS differences in individuals with vertebral exclusions due to structural artifact on TBS-adjusted FRAX-based treatment recommendations. We identified 71,209 individuals aged ≥40 years with TBS and FRAX calculations through the Manitoba Bone Density Program. In the 24,428 individuals with vertebral exclusions, adjusting TBS using these level-specific factors agreed with TBSL1-L4 (mean difference -0.001). We compared FRAX-based treatment recommendations for TBSL1-L4 and for non-excluded vertebral levels before and after adjusting for level-specific TBS differences. Among those with baseline major osteoporotic fracture risk ≥15 %, TBS with vertebral exclusions reclassified FRAX-based treatment in 10.6 % of individuals compared with TBSL1-L4, and was reduced to 7.2 % after adjusting for level-specific differences. In 11,131 patients where L1-L2 was used for BMD reporting (the most common exclusion pattern with the largest TBS effect), treatment reclassification was reduced from 13.9 % to 2.4 %, respectively. Among individuals with baseline hip fracture risk ≥2 %, TBS vertebral exclusions reclassified 7.1 % compared with TBSL1-L4, but only 4.5 % after adjusting for level-specific differences. When L1-L2 was used for BMD reporting, treatment reclassification from hip fracture risk was reduced from 9.2 % to 5.2 %. In conclusion, TBS and TBS-adjusted FRAX-based treatment recommendations are affected by vertebral level exclusions for structural artifact. Adjusting for level-specific differences in TBS reduces reclassification in FRAX-based treatment recommendations.

FRAX® Adjustment Using Renormalized Trabecular Bone Score (TBS) from L1 Alone may be Optimal for Fracture Prediction: The Manitoba BMD Registry

Lumbar spine trabecular bone score (TBS) used in conjunction with FRAX® improves 10-year fracture prediction. The derived FRAX risk adjustment is based upon TBS measured from L1-L4, designated TBSL1-L4-FRAX. In prior studies, TBS measurements that include L1 and exclude L4 give better fracture stratification than L1-L4. We compared risk stratification from TBS-adjusted FRAX using TBS derived from different combinations of upper lumbar vertebral levels renormalized for level-specific differences in individuals from the Manitoba Bone Density Program aged >40 years with baseline assessment of TBS and FRAX. TBS measurements for L1-L3, L1-L2 and L1 alone were calculated after renormalization for level-specific differences. Corresponding TBS-adjusted FRAX scores designated TBSL1-L3-FRAX, TBSL1-L2-FRAX and TBSL1-FRAX were compared with TBSL1-L4-FRAX for fracture risk stratification. Incident major osteoporotic fractures (MOF) and hip fractures were assessed. The primary outcome was incremental change in area under the curve (ΔAUC). The study population included 71,209 individuals (mean age 64 years, 89.8% female). Before renormalization, mean TBS for L1-3, L1-L2 and L1 was significantly lower and TBS-adjusted FRAX significantly higher than from using TBSL1-L4. These differences were largely eliminated when TBS was renormalized for level-specific differences. During mean follow-up of 8.7 years 6745 individuals sustained incident MOF and 2039 sustained incident hip fractures. Compared with TBSL1-L4-FRAX, use of FRAX without TBS was associated with lower stratification (ΔAUC = -0.009, p < 0.001). There was progressive improvement in MOF stratification using TBSL1-L3-FRAX (ΔAUC = +0.001, p < 0.001), TBSL1-L2-FRAX (ΔAUC = +0.004, p < 0.001) and TBSL1-FRAX (ΔAUC = +0.005, p < 0.001). TBSL1-FRAX was significantly better than all other combinations for MOF prediction (p < 0.001). Incremental improvement in AUC for hip fracture prediction showed a similar but smaller trend. In conclusion, this single large cohort study found that TBS-adjusted FRAX performance for fracture prediction was improved when limited to the upper lumbar vertebral levels and was best using L1 alone.

Effects of Severe Lumbar Spine Structural Artifact on Trabecular Bone Score (TBS): The Manitoba BMD Registry

Trabecular bone score (TBS) is a bone mineral density (BMD)-independent risk factor for fracture. During DXA analysis and BMD reporting, it is standard practice to exclude lumbar vertebral levels affected by structural artifact. Although TBS is relatively insensitive to degenerative artifact, it is uncertain whether TBS is still useful in the presence extreme structural artifact that precludes reliable spine BMD measurement even after vertebral exclusions. Among individuals aged 40 years and older undergoing baseline DXA assessment from September 2012 to March 2018 we identified three mutually exclusive groups: spine BMD reporting performed without exclusions (Group 1, N=12,865), spine BMD reporting performed with vertebral exclusions (Group 2, N=4867), and spine BMD reporting not performed due to severe structural artifact (Group 3, N=1541). No significant TBS difference was seen for Group 2 versus Group 1 (referent), whereas TBS was significantly greater in Group 3 (+0.041 partially adjusted, +0.043 fully adjusted). When analyzed by the reason for vertebral exclusion, multilevel degenerative changes significantly increased TBS (+0.041 partially adjusted, +0.042 fully adjusted), while instrumentation significantly reduced TBS (-0.059 partially adjusted, -0.051 fully adjusted). Similar results were seen when analyses were restricted to those in Group 3 with a single reason for vertebral exclusions, and when follow up scans were also included. During mean follow-up of 2.5 years there were 802 (4.2 %) individuals with one or more incident fractures. L1-L4 TBS showed significant fracture risk stratification in all groups including Group 3 (P-interaction >0.4). In conclusion, lumbar spine TBS can be reliably measured in the majority of lumbar spine DXA scans, including those with artifact affecting up to two vertebral levels. However, TBS is significantly affected by the presence of extreme structural artifact in the lumbar spine, especially those with multilevel degenerative disc changes and/or instrumentation that precludes reliable BMD reporting.

Trabecular Bone Score Vertebral Exclusions Affect Risk Classification and Treatment Recommendations: The Manitoba Bmd Registry

Lumbar spine trabecular bone score (TBS), a texture measure derived from spine dual-energy x-ray absorptiometry (DXA) images, is a bone mineral density (BMD)-independent risk factor for fracture. Lumbar vertebral levels that show structural artifact are excluded from BMD measurement. TBS is relatively unaffected by degenerative artifact, and it is uncertain whether the same exclusions should be applied to TBS reporting. To gain insight into the clinical impact of vertebral exclusion on TBS, we examined the effect of lumbar vertebral exclusions in routine clinical practice on tertile-based TBS categorization and TBS adjusted FRAX-based treatment recommendations. The study population consisted of 71,209 individuals aged 40 years and older with narrow fan-beam spine DXA examinations and retrospectively-derived TBS. During BMD reporting, 34.3% of the scans had one or more vertebral exclusions for structural artifact. When TBS was derived from the same vertebral levels used for BMD reporting, using fixed L1-L4 tertile cutoffs (1.23 and 1.31 from the McCloskey meta-analysis) reclassified 17.9% to a lower and 6.5% to a higher TBS category, with 75.6% unchanged. Reclassification was reduced from 24.4% overall to 17.2% when level-specific tertile cutoffs from the software manufacturer were used. Treatment reclassification based upon FRAX major osteoporotic fracture probability occurred in 2.9% overall, but in 9.6% of those with baseline risk ≥15%. For treatment based upon FRAX hip fracture probability, reclassification occurred in 3.4% overall, but in 10.4% in those with baseline risk ≥2%. In summary, lumbar spine TBS measurements based upon vertebral levels other than L1-L4 can alter the tertile category and treatment recommendations based upon TBS-adjusted FRAX calculation, especially for those close to or exceeding the treatment cut-off. Manufacturer level-specific tertile cut-offs should be used if vertebral exclusions are applied.

Vertebral Level Variations in Trabecular Bone Score and Effect on Fracture Prediction: The Manitoba BMD Registry

Trabecular bone score (TBS), a texture measure derived from spine dual-energy x-ray absorptiometry (DXA) images, is a bone mineral density (BMD)-independent risk factor for fracture. TBS is reportedly insensitive to degenerative changes, and it is uncertain whether the same rules for excluding lumbar vertebral levels from BMD measurement should be applied to TBS. The current analysis was performed to explore inter-vertebral variation in TBS measurements from L1 to L4, how this relates to clinically identified structural artifact resulting in vertebral level exclusion from BMD reporting, and area under the curve (AUC) for incident fracture. The study population comprised 70,762 individuals aged 40 years and older at the time of baseline spine DXA assessment (mean age 64.1 years, 89.7% female), among whom 24,289 (34.3%) had one or more vertebral exclusions. Both TBS and BMD showed a similar cranial/caudal inter-vertebral gradient. Compared with L1-4, TBS from L1 alone was lower (mean difference -0.096; -7.6%) while TBS from L4 alone was 0.046 (3.6%) greater, similar in those without and with visual structural artifact. During mean follow-up of 8.7 years, 6744 (9.5%) individuals sustained incident major osteoporotic fractures. TBS from L1 alone gave significantly higher AUC for incident fracture than L1-4, which was in turn significantly higher than L2, L3 and L4 alone, seen in those without and with visual structural artifact. In contrast, AUCs for BMD showed minimal variation from L1 to L4, and was higher for L1-4 than for any individual lumbar vertebral level. In summary, we found inter-vertebral TBS variations within the lumbar spine are overall similar to BMD but are relatively unaffected by visual structural artifact. Fracture outcomes showed the strongest association with TBS measured from L1 alone. Further investigation is need to understand the cause and clinical application of these differences.

Update on trabecular bone score

Trabecular bone score (TBS) is an indirect and noninvasive measure of bone quality. A low TBS indicates degraded bone microarchitecture, predicts osteoporotic fracture, and is partially independent of clinical risk factors and bone mineral density (BMD). There is substantial evidence supporting the use of TBS to assess vertebral, hip, and major osteoporotic fracture risk in postmenopausal women, as well as to assess hip and major osteoporotic fracture risk in men aged > 50 years. TBS complements BMD information and can be used to adjust the FRAX (Fracture Risk Assessment) score to improve risk stratification. While TBS should not be used to monitor antiresorptive therapy, it may be potentially useful for monitoring anabolic therapy. There is also a growing body of evidence indicating that TBS is particularly useful as an adjunct to BMD for fracture risk assessment in conditions associated with increased fracture risk, such as type-2 diabetes, chronic corticosteroid excess, and other conditions wherein BMD readings are often misleading. The interference of abdominal soft tissue thickness (STT) on TBS should also be considered when interpreting these findings because image noise can impact TBS evaluation. A new TBS software version based on an algorithm that accounts for STT rather than BMI seems to correct this technical limitation and is under development. In this paper, we review the current state of TBS, its technical aspects, and its evolving role in the assessment and management of several clinical conditions.

Usefulness of the Trabecular Bone Score in Assessing the Risk of Vertebral Fractures in Patients with Cirrhosis

The trabecular bone score (TBS), a surrogate measure of bone microarchitecture, provides complementary information to bone mineral density (BMD) in the assessment of osteoporotic fracture risk. This cross-sectional study aimed to determine whether TBS can identify patients with liver cirrhosis that are at risk of vertebral fractures. We enrolled 275 patients who completed evaluations for lumbar BMD, TBS, and vertebral fractures between November 2018 and April 2021. BMD was measured using dual-energy X-ray absorptiometry (DXA), TBS was calculated by analyzing DXA images using TBS iNsight software, and vertebral fractures were evaluated using Genant’s semi-quantitative method with lateral X-ray images. Factors associated with vertebral fractures and their correlation with the TBS were identified using regression models. Of the enrolled patients, 128 (47%) were female, the mean age was 72 years, and 62 (23%) were diagnosed with vertebral fractures. The prevalence of vertebral fractures was higher in women than in men (33% vs. 14%; p < 0.001). The unadjusted odds ratio (OR) of the vertebral fractures for one standard deviation decrease in TBS and BMD was 2.14 (95% confidence interval [CI], 1.69−2.73) and 1.55 (95% CI, 1.26−1.90), respectively. After adjusting for age, sex, and BMD, the adjusted OR of the vertebral fractures in TBS was 2.26 (95% CI, 1.52−3.35). Multivariate linear regression analysis showed that TBS was independently correlated with age (β = −0.211), body mass index (β = −0.251), and BMD (β = 0.583). TBS can help identify patients with cirrhosis at risk of vertebral fractures.

Abnormal Trabecular Bone Score, Lower Bone Mineral Density and Lean Mass in Young Women With Premature Ovarian Insufficiency Are Prevented by Oestrogen Replacement

BACKGROUND

Low bone density (BMD) and fractures commonly affect women with premature ovarian insufficiency (POI). However, bone microarchitecture and body composition data are lacking.

OBJECTIVE

To assess and characterise musculoskeletal phenotype and effects of oestrogen replacement therapy (ERT) in women with POI.

METHOD

Cross-sectional and longitudinal studies of 60 normal karyotype women with POI, aged 20-40 years, from 2005-2018. Dual x-ray absorptiometry (DXA)-derived spinal (LS) and femoral neck (FN) BMD, trabecular bone score (TBS), appendicular lean mass (ALM), total fat mass (TFM), and fracture prevalence were compared with 60 age-, and BMI-matched population-based controls. Longitudinal changes in bone and body composition variables and ERT effects were analysed using linear mixed models over a median duration of 6 years.

RESULTS

Women with POI were subdivided into spontaneous (s)-POI (n=25) and iatrogenic (i)-POI (n=35). Median(range) age of POI diagnosis was 34 (10-40) years with baseline DXA performed at median 1(0-13) year post-diagnosis. ERT was used by 82% women (similar for both POI groups). FN-BMD were lowest in s-POI (p<0.002). Low TBS was more common in s-POI [(44%), p=0.03], versus other groups. LS-BMD and ALM were lower in both s-POI and i-POI groups than controls (p<0.05). Fracture prevalence was not significantly different: 20% (s-POI), 17% (i-POI), and 8% (controls) (p=0.26). Longitudinal analysis of 23 POI women showed regular ERT was associated with ALM increment of 127.05 g/year (p<0.001) and protected against bone loss. However, ERT interruption was associated with annual reductions in FN BMD and TBS of 0.020g/cm² and 0.0070 (p<0.05), respectively.

CONCLUSION

Deficits in BMD, trabecular microarchitecture, and lean mass were present in women with POI. However, regular ERT protected against declines in bone variables, with an increase in ALM. Assessment of skeletal and muscle health, and advocating ERT adherence, is essential in POI to optimise musculoskeletal outcomes.

Analysis of Influencing Factors of Medication Compliance in Patients with Recurrent Vertebral Fractures after Percutaneous Kyphoplasty and the Role of Family-Centered Education Intervention

OBJECTIVE

To explore the influencing factors of medication compliance in patients with recurrent vertebral fractures after percutaneous kyphoplasty (PKP) and the role of family-centered education intervention.

METHODS

From January 2018 to January 2021, the general disease-related data survey form and medication compliance questionnaire made by our hospital were used to evaluate the scores of 198 patients with recurrent vertebral fractures after PKP in the Department of Orthopedics of our hospital. Single-factor and multiple linear regression analyses were used to explore the influencing factors of medication compliance in patients with recurring vertebral fractures after PKP. From 198 patients, 80 eligible patients were selected for further research. According to a random number table method, they were divided into the control group (n = 40) given only antiosteoporosis drug treatment and care and the experimental group (n = 40) combined with family-centered education intervention. After 12 months of intervention, the two groups were evaluated for their knowledge of osteoporosis, medication compliance, and physical health.

RESULTS

Of the 198 patients, only 65 had good medication compliance, 90 had poor medication compliance, and 43 were acceptable. Univariate analysis showed that the influencing factors of medication compliance in patients with recurrent vertebral fractures after PKP include the patient's education, living style, per capita monthly income, combined other diseases, number of hospitalizations, and time since the last hospitalization (P < 0.05). Multiple linear regression analysis showed that patients with recurring vertebral fractures after PKP with high education, living with spouse or children, combined with other diseases, frequent hospitalizations, and short time from the last hospitalization had higher medication compliance (P < 0.05). After the intervention, the disease knowledge mastery of the experimental group was significantly better than before and after the intervention in the control group (P < 0.0001). After the intervention, the medication compliance and health status of the experimental group were significantly better than those of the control group (P < 0.05).

CONCLUSION

The medication compliance of patients with recurrent vertebral fractures after PKP is generally poor, and medical staff need to take targeted interventions based on the main factors that affect the patients' medication compliance. Family-centered education intervention is an effective way to improve disease awareness, medication compliance, and health status of patients with recurring vertebral fractures after PKP.

Association of short sleep duration and trabecular bone score

Short sleep duration has been found to be associated with bone health deterioration by using bone mineral density (BMD). Only a few attempts have been made to assess the association of sleep duration and bone by utilizing the trabecular bone score (TBS). The aim of this study was to examine the association between sleep duration and TBS from a national database. A total of 4480 eligible participants older than 20 years who attended the United States National Health and Nutrition Examination Survey (NHANES) from 2005 to 2006 with TBS data and self-reported sleep duration. The association between sleep duration and TBS was investigated using a multivariate regression model with covariate adjustment. TBS was lowest in individuals with a short sleep duration (≤ 5 h) and it was increased in those with longer self-reported total sleep times. After a full adjustment for covariates, those sleeping less than 5 h had a significantly lower TBS than the reference group (sleep duration of 7 h). In subgroup analyses, an association between short sleep duration (≤ 5 h) and lower TBS persisted in older ages (≥ 60 years old), women, obese adults (BMI ≥ 30 kg/m²), and non-Hispanic Whites. Short sleep duration is associated with low TBS in women, obese adults (BMI ≥ 30 kg/m²), and non-Hispanic whites. Strict self-monitoring of body weight, well-tailored controls of underlying disease(s), and adequate sleep may help prevent osteoporosis.