Prevalent osteoporotic vertebral fractures more likely involve the upper endplate than the lower endplate and even more so in males

Towards the diagnosis of osteoporosis - contributions from coincidental diagnostic imaging findings in chiropractors' practice

BACKGROUND

Osteoporosis is significantly associated with fractures and burdens the health of especially older people. Osteoporotic fractures cause pain, disability, and increased mortality. Early diagnosis of osteoporosis allows earlier initiation of treatment, thereby reducing the risk of osteoporotic fractures. Chiropractors encounter potential osteoporotic patients daily, and perform radiological evaluation of these and other patients, including evaluation of X-rays done for other purposes than osteoporosis. Therefore, chiropractors may identify vertebral fractures, vertebral deformity or osteopenia not otherwise suspected or recorded.

METHODS

This study examines procedures available to the chiropractor to describe conventional X-rays with the focus of osteoporosis related findings. We review the indications for radiological examination in chiropractic practice, and in the realm of osteoporosis we describe radiological methods available for examination of conventional radiographs, and the necessity of inter-disciplinary communication.

RESULTS

National guidelines are available regarding referral for X-rays in chiropractic practice. Standardized protocols ensure image acquisition of the highest quality in the chiropractors' radiological department. Conventional X-ray examination is not indicated on clinical suspicion of osteoporosis alone, as bone mineral density testing is the diagnostic test. Radiological assessment of all available X-rays of patients above the age of 50 years should include evaluation of the bone quality, and hip and vertebral fracture assessment. The Singh index, Genant Semi-Quantitative tool (GSQ), and Algorithm-Based Qualitative method (ABQ) should be used consistently during interpretation. Referral for additional imaging and evaluation should be prompt and systematic when needed.

CONCLUSIONS

This article presents an overview of evidence-based radiological procedures for the purpose of promoting early diagnosis of osteoporosis. We present recommendations to the clinicians where we propose an opportunistic evaluation of X-rays, done for any reason, which include systematic evaluation of bone quality, presence of hip and vertebral fractures, and vertebral deformation of all patients above the age of 50 years. Detailed referral to healthcare professionals for further diagnostic evaluation is performed when needed. Consistent, high-quality radiological procedures in chiropractic practices could feasibly contribute to the timely diagnosis of osteoporosis, ultimately minimizing the impact of osteoporosis-related complications on patients' health.

Stimuli-Responsive Delivery Systems for Intervertebral Disc Degeneration

As a major cause of low back pain, intervertebral disc degeneration is an increasingly prevalent chronic disease worldwide that leads to huge annual financial losses. The intervertebral disc consists of the inner nucleus pulposus, outer annulus fibrosus, and sandwiched cartilage endplates. All these factors collectively participate in maintaining the structure and physiological functions of the disc. During the unavoidable degeneration stage, the degenerated discs are surrounded by a harsh microenvironment characterized by acidic, oxidative, inflammatory, and chaotic cytokine expression. Loss of stem cell markers, imbalance of the extracellular matrix, increase in inflammation, sensory hyperinnervation, and vascularization have been considered as the reasons for the progression of intervertebral disc degeneration. The current treatment approaches include conservative therapy and surgery, both of which have drawbacks. Novel stimuli-responsive delivery systems are more promising future therapeutic options than traditional treatments. By combining bioactive agents with specially designed hydrogels, scaffolds, microspheres, and nanoparticles, novel stimuli-responsive delivery systems can realize the targeted and sustained release of drugs, which can both reduce systematic adverse effects and maximize therapeutic efficacy. Trigger factors are categorized into internal (pH, reactive oxygen species, enzymes, etc.) and external stimuli (photo, ultrasound, magnetic, etc.) based on their intrinsic properties. This review systematically summarizes novel stimuli-responsive delivery systems for intervertebral disc degeneration, shedding new light on intervertebral disc therapy.

A comparison of radiographic degeneration features of older Chinese women and older Italian Caucasian women with a focus on thoracic spine

BACKGROUND

Compared with Caucasians, East Asians have a lower incident of back pain, lower prevalence and severity of osteoporotic vertebral fracture and lumbar spine degeneration.

AIM

This study compares radiographic spine degeneration features of older Chinese women (as an example of East Asians) and older Italian women (as an example of Caucasians) with a focus on the thoracic spine.

METHODS

From two population-based epidemiological studies conducted in Hong Kong, China and Rome, Italy, 297 pairs (mean age: 73.6 years) age-matched older community women's lateral spine radiographs were sampled. Existence (or absence) of seven degeneration features were assessed including: (1) hyper-kyphosis, (2) disc space narrowing (T3/T4 ~ T11/T12), (3) osteoarthritic (OA) wedging (T4 ~ T12), (4) generalised osteophyte formation (T4 ~ T12); (5) acquired short vertebrae (T4 ~ T12), (6) Schmorl node (T4 - L5), (7) disc calcification (T4-L5).

RESULTS

Italian women were more likely to have hyper-kyphosis (53.4% vs 25.6%), disc space narrowing (34.4% vs. 17.2%), OA wedging (6.4% vs. 0.67%), Schmorl node (19.5% vs. 4.4%, all P < 0.001). However, there was no statistically significant difference in osteophyte formation (7.7% vs. 9.4%, P > 0.1) and acquired short vertebrae (8.0% vs. 10.4%, P > 0.1). Disc calcification was uncommon among both Chinese and Italians.

DISCUSSION AND CONCLUSION

For the first time, this study documented a lower prevalence of a number of thoracic spine degeneration features among Chinese. This study further affirms the concept of a generally healthier spine in older Chinese relative to older Caucasians. The observed differences may reflect a foundational background influence of genetic predisposition that represents an important line of future research.

Trabecular structural difference between the superior and inferior regions of the vertebral body: a cadaveric and clinical study

Background

Osteoporotic vertebral compression fractures commonly involve the superior vertebral body; however, their associated causes have not yet been clearly established. This study aimed to determine the trabecular structural differences between the superior and inferior regions of the vertebral body using cadaveric and clinical studies.

Materials and methods

First, five vertebrae were collected from three human cadavers. The trabecular structures of the superior and inferior regions of each vertebral body were analyzed using micro-computed tomography (micro-CT), finite element analysis (FEA), and biomechanical test. Based on the results of the ex vivo study, we conducted a clinical study. Second, spine CT images were retrospectively collected. Bone volume and Hounsfield unit were analyzed for 192 vertebral bodies. Finally, after sample size calculation based on the pilot study, prospectively, 200 participants underwent dual-energy X-ray absorptiometry (DXA) of the lateral spine. The bone mineral densities (BMDs) of the superior and inferior regions of each lumbar vertebral body were measured. The paired t-test and Wilcoxon signed-rank test were used for the statistical analyses, and p-value < 0.05 was considered significant.

Results

Cadaver studies revealed differences between the superior and inferior trabecular bone structures. The bone volume ratio, BMD, and various other trabecular parameters advocated for decreased strength of the superior region. Throughout the biomechanical study, the limitations of the compression force were 3.44 and 4.63 N/m2 for the superior and inferior regions, respectively. In the FEA study, the inferior region had a lower average displacement and higher von Mises stress than the superior region. In the clinical spine CT-based bone volume and BMD study, the bone volume was significantly higher in the inferior region than in the superior region. In the lateral spine DXA, the mean BMD of the superior region of vertebral bodies was significantly lower compared with that of the inferior region.

Conclusion

The superior trabecular structure of the lumbar vertebral bodies possesses more biomechanical susceptibility compared with the inferior trabecular structure, confirming its dominant role in causing osteoporotic vertebral fractures. Physicians should also focus on the BMD values of the superior region of the vertebral body using lateral spine DXA to evaluate osteoporosis.

Biomechanical comparison of pedicle screw fixation strength among three different screw trajectories using single vertebrae and one-level functional spinal unit

Three key factors are responsible for the biomechanical performance of pedicle screw fixation: screw mechanical characteristics, bone quality and insertion techniques. To the best of the authors' knowledge, no study has directly compared the biomechanical performance among three trajectories, i.e., the traditional trajectory (TT), modified trajectory (MT) and cortical bone trajectory (CBT), in a porcine model. This study compared the pullout strength and insertion torque of three trajectory methods in single vertebrae, the pullout strength and fixation stiffness including flexion, extension, and lateral bending in a one-level instrumented functional spinal unit (FSU) that mimics the in vivo configuration were clarified. A total of 18 single vertebrae and 18 FSUs were randomly assigned into three screw insertion methods (n = 6 in each trajectory group). In the TT group, the screw converged from its entry point, passed completely inside the pedicle, was parallel to the superior endplate, was located in the superior third of the vertebral body and reached to at least the anterior third of the vertebral body. In the MT group, the convergent angle was similar to that of the TT method but directed caudally to the anterior inferior margin of the vertebral body. The results of insertion torque and pullout strength in single vertebrae were analyzed; in addition, the stiffness and pullout strength in the one-level FSU were also investigated. This study demonstrated that, in single vertebrae, the insertion torque was significantly higher in CBT groups than in TT and MT groups (p < 0.05). The maximal pullout strength was significantly higher in MT groups than in TT and CBT groups (p < 0.05). There was no significant difference in stiffness in the three motions among all groups. The maximal pullout strength in FSUs of MT and CBT groups were significantly higher than the TT groups (p < 0.05). We concluded that either MT or CBT provides better biomechanical performance than TT in single vertebrae or FSUs. The lack of significance of stiffness in FSUs among three methods suggested that MT or CBT could be a reasonable alternative to TT if the traditional trajectory was not feasible.

New Progress in Basic Research of Macrophages in the Pathogenesis and Treatment of Low Back Pain

Low back pain (LBP) is quite common in clinical practice, which can lead to long-term bed rest or even disability. It is a worldwide health problem remains to be solved. LBP can be induced or exacerbated by abnormal structure and function of spinal tissue such as intervertebral disc (IVD), dorsal root ganglion (DRG) and muscle; IVD degeneration (IVDD) is considered as the most important among all the pathogenic factors. Inflammation, immune response, mechanical load, and hypoxia etc., can induce LBP by affecting the spinal tissue, among which inflammation and immune response are the key link. Inflammation and immune response play a double-edged sword role in LBP. As the main phagocytic cells in the body, macrophages are closely related to body homeostasis and various diseases. Recent studies have shown that macrophages are the only inflammatory cells that can penetrate the closed nucleus pulposus, expressed in various structures of the IVD, and the number is positively correlated with the degree of IVDD. Moreover, macrophages play a phagocytosis role or regulate the metabolism of DRG and muscle tissues through neuro-immune mechanism, while the imbalance of macrophages polarization will lead to more inflammatory factors to chemotaxis and aggregation, forming an "inflammatory waterfall" effect similar to "positive feedback," which greatly aggravates LBP. Regulation of macrophages migration and polarization, inhibition of inflammation and continuous activation of immune response by molecular biological technology can markedly improve the inflammatory microenvironment, and thus effectively prevent and treat LBP. Studies on macrophages and LBP were mainly focused in the last 3-5 years, attracting more and more scholars' attention. This paper summarizes the new research progress of macrophages in the pathogenesis and treatment of LBP, aiming to provide an important clinical prevention and treatment strategy for LBP.

'Healthier Chinese spine': an update of osteoporotic fractures in men (MrOS) and in women (MsOS) Hong Kong spine radiograph studies

For the MrOS (Hong Kong) and MsOS (Hong Kong) baseline (BL) studies, community-dwelling 2,000 Chinese men (mean age: 72.3 years) and 2,000 Chinese women (mean age: 72.5 years) were recruited from 2001 to 2003. These two studies have spanned two decades till now. This review summarizes our spine radiograph results. Senile and post-menopausal osteoporosis were associated with intervertebral disc volume reduction; and in women, menopause accelerates disc degeneration. Elderly women's osteoporotic vertebral fracture (OVF) prevalence was double of that of elderly men. For year-4 follow-up (FU), male participants with BL OVF had little increased risk for further OVF. In our study comparing OVF rates in age-matched Hong Kong Chinese women and Italian Caucasian women (mean age: 74.1 years), endplate and/or cortex fracture (ECF) prevalence was 26% for Chinese and 47% for Italian. OVF with ≥40% vertebral height loss was recorded among 9.5% of the Chinese subjects while among 26% of the Italian subjects. OVFs in Italian subjects were more likely to be multiple and generally severer. Clinical spine fractures were recorded 133 cases/100,000 person-years in MrOS (Hong Kong) participants and 273 cases/100,000 person-years in MsOS (Hong Kong) participants. Literature review suggests the clinical vertebral fracture rates among elderly Hong Kong Chinese subjects are approximately half of those of American, Australian, and Canadian subjects. Data synthesis suggests elderly Caucasians have a higher degenerative spondylolisthesis prevalence, being approximately 70% higher than that of elderly Hong Kong Chinese. Literature review of other authors' publications shows, compared with Caucasians, Chinese have a much lower incident rate of back pain. We conclude that elderly Chinese have a generally healthier spine relative to elderly Caucasians.

Panax notoginseng saponins attenuate intervertebral disc degeneration by reducing the end plate porosity in lumbar spinal instability mice

Although painkillers could alleviate some of the symptoms, there are no drugs that really cope with the intervertebral disc degeneration (IDD) at present, so it is urgent to find a cure that could prevent or reverse the progression of IDD. During the development of IDD, the cartilaginous end plates (EPs) become hypertrophic and porous by the increase of osteoclast activities, which hinder the penetration of nutrition. The compositional and structural degeneration of the EP may cause both nutritional as well as mechanical impairment to the nucleus pulposus (NP) so that developing drugs that target the degenerating EP may be another option in addition to targeting the NP. In the lumbar spine instability mouse model, we found increased porosity in the cartilaginous EP, accompanied by the decrease in total intervertebral disc volume. Panax notoginseng saponins (PNS), a traditional Chinese patent drug with anti-osteoclastogenesis effect, could alleviate IDD by inhibiting aberrant osteoclast activation in the porous EP. Further in vitro experiment validated that PNS inhibit the receptor activator of nuclear factor kappa-Β ligand-induced osteoclast differentiation, while the transcriptional activation of PAX6 may be involved in the mechanism, which had been defined as an inhibitory transcription factor in osteoclastogenesis. These findings may provide a novel therapeutic strategy for IDD.

Proper animal experimental designs for preclinical research of biomaterials for intervertebral disc regeneration

Low back pain is a vital musculoskeletal disease that impairs life quality, leads to disability and imposes heavy economic burden on the society, while it is greatly attributed to intervertebral disc degeneration (IDD). However, the existing treatments, such as medicines, chiropractic adjustments and surgery, cannot achieve ideal disc regeneration. Therefore, advanced bioactive therapies are implemented, including stem cells delivery, bioreagents administration, and implantation of biomaterials etc. Among these researches, few reported unsatisfying regenerative outcomes. However, these advanced therapies have barely achieved successful clinical translation. The main reason for the inconsistency between satisfying preclinical results and poor clinical translation may largely rely on the animal models that cannot actually simulate the human disc degeneration. The inappropriate animal model also leads to difficulties in comparing the efficacies among biomaterials in different reaches. Therefore, animal models that better simulate the clinical charateristics of human IDD should be acknowledged. In addition, in vivo regenerative outcomes should be carefully evaluated to obtain robust results. Nevertheless, many researches neglect certain critical characteristics, such as adhesive properties for biomaterials blocking annulus fibrosus defects and hyperalgesia that is closely related to the clinical manifestations, e.g., low back pain. Herein, in this review, we summarized the animal models established for IDD, and highlighted the proper models and parameters that may result in acknowledged IDD models. Then, we discussed the existing biomaterials for disc regeneration and the characteristics that should be considered for regenerating different parts of discs. Finally, well-established assays and parameters for in vivo disc regeneration are explored.

Radiological features of traumatic vertebral endplate fracture: an analysis of 194 cases with 263 vertebral fractures

BACKGROUND

The importance of identifying osteoporotic vertebral endplate or/and cortex fracture (ECF), which primarily includes endplate fracture (EPF) and vertebral anterior cortex buckling, has been recognized. However, some old traumatic ECFs with healing process in the elderly may be mistaken as osteoporotic. This study analyzes the radiological features of traumatic EPF.

METHODS

This was a retrospective analysis of 194 spine trauma patients with 263 vertebral fractures (mean age: 42.11 ± 9.82 years, 118 males and 76 females). All patients had traumatic EPF identified by X-ray/CT/MRI.

RESULTS

The involved vertebra was mostly L1 (29.7%), followed by T12 and L2. Except EPFs involved both superior and inferior endplates (12.6%), only 1.9% involved inferior endplate alone, with the majority involved superior endplate. If each endplate was divided into five segments of equal lengths (from anterior to posterior: a1, a2, m, p2, p1), the most depressed point of superior EPFs was mostly at segment-a2 (approximately 45%), followed by segment-a1 (approximately 20%) or segment-m (approximately 20%), and very rarely at segment-p1. The upper 1/3 of anterior vertebral wall was more likely to fracture, followed by middle 1/3 of anterior wall. For posterior vertebral wall fracture, 68.5% broke the bony wall surrounding the basivertebral vain. 58.6%, 30.0%, and 11.4% of vertebral fractures had <1/5, 1/5-1/3, and >1/3 vertebral body height loss. As the extent of vertebral height loss increased, the chance of having both superior and inferior EPFs also increased; however, the chance of having inferior EPF alone did not increase.

CONCLUSION

Traumatic EPF features are characterized, which may help the differentiation of traumatic and osteoporotic EPFs.

Elderly men have much lower vertebral fracture risk than elderly women even at advanced age: the MrOS and MsOS (Hong Kong) year 14 follow-up radiology results

MrOS MsOS (Hong Kong) studies year 14 follow-up shows for subjects without baseline osteoporotic vertebral deformity, women's incident vertebral fracture (VF) rate was twice that of men. For subjects with vertebral deformity of baseline ≥ 20% height loss, counting subject, women's incident VF rate was three times higher than that of men.

INTRODUCTION

For MrOS MsOS (Hong Kong) baseline (BL) studies, 2000 men and 2000 women ≥ 65 years were recruited during 2001 to 2003. This study presents the year 14 follow-up (FU).

MATERIALS

Whole spine MRI was performed in 271 males (mean, 82.8 ± 3.6 years) and 150 females (mean, 82.0 ± 4.29 years). Osteoporotic vertebral deformity (OVD) classification included no OVD (grade 0), and OVDs with < 20%, 20~25%, > 25%~1/3, > 1/3~40%, > 40%~2/3, and > 2/3 height loss (grade 1~6). With an existing VD, a further height loss of ≥ 15% was a VD progression. A new incident VD was a change from grade 0 to ≥ grade 2 or to grade 1 with ≥ 10% height loss. OVD progression and new incident OVD were considered incident VF.

RESULTS

The proportion of osteoporotic subjects only slightly increased during FU for men but doubled for women. Groupwise, OVD was not associated with back pain in men; but OVD with > 1/3 height loss was associated with back pain in women. For subjects without BL OVD, 7.9% of men and 14.6% of women had incident VF. For subjects with BL OVD of ≥ 20% height loss, men's and women's incident VF were 17.6% and 52.6%, respectively, counting subject and 1.68% and 7.89%, respectively, counting vertebra.

CONCLUSION

Elderly men with or without existing osteoporotic VD have much lower future VF risk than elderly women.

Traumatic vertebral fractures involve the anterior end plate more than the posterior end plate: A retrospective study

Traumatic end plate fractures (EPFs) refers to the EPF caused by trauma, rather than the pathological status of the end plate (EP). However, some old traumatic EPFs may be mistaken as osteoporotic in the elderly. The objective of this study is to describe the radiological features of traumatic EPF in different traumatic fracture type patients presenting in the Emergency department setting. And to compare the result with osteoporotic vertebral fracture (VF).This study retrospectively analyzed the anatomical location of acute thoracolumbar vertebral traumatic EPFs in males (age≤55 years) and females (age≤50 years). The anatomic distribution of EPFs, the anterior and posterior wall fracture were analyzed in patients, who were scanned with 1 or more of the following methods: radiography, CT, and magnetic resonance imaging.There were 194 cases of acute spine trauma involving at least 1 EPF, including 118 males and 76 females. The involved vertebra was mostly at L1 (29.7%), followed by T12 (18.3%), and then by L2 (12.9%). Excluding those with both upper and lower EP involvements, the ratio of superior EPF to inferior EPF was 33.5 for males and 45.5 for females. With the EP divided into 5 segments of equal length in the anteroposterior direction in different fracture types, fractures occurred mostly at a2 segment (71.48% for superior EPs and 7.60% for inferior EPs), followed by a1 segment (66.16% for superior EPs). The upper third of the anterior and posterior walls were most prone to fracture in traumatic vertebral fracture.Traumatic EPFs more likely involve the anterior EP more than the posterior EP and is correlated with fracture type. These characteristics may help radiologist differential diagnosis between traumatic and osteoporotic EPF.

Risk factors of adjacent segmental fractures when percutaneous vertebroplasty is performed for the treatment of osteoporotic thoracolumbar fractures

The study aimed to analyze the radiographic and magnetic resonance imaging (MRI) findings that might predict the risk for adjacent segmental fractures (ASFs) when percutaneous vertebroplasty (PV) is used for the treatment of osteoporotic thoracolumbar fractures (OTFs). A total of 92 OTFs patients who underwent PV between January 2013 and January 2015 were retrospectively reviewed. The visual analog scale (VAS), Oswestry-Disability Index (ODI) and radiolographic measurements were assessed. The VAS and ODI scores improved significantly at the final follow-up (FU) compared with the preoperation scores. Compared with the preoperative values, the fractured body alignment (FBA) significantly improved at the 3-month FU and the final FU, but the adjacent segment alignment (ASA) and thoracolumbar alignment (TLA) did not improve. According to the correlation analysis, the final FU TLA and the final FU ASA were correlated with the preoperative FBA, ASA, and TLA on plain radiography and were highly correlated on MRI. However, the final FU FBA was not correlated with the preoperative FBA, ASA, or TLA on plain radiography or MRI (P > 0.05). The ASFs were correlated with the 3-month FU TLA (r = 0.6044, P = 0.0037) and the final FU TLA (r = 0.5699, P = 0.007) on plain radiography, and the final TLA was more correlated with the preoperative FBA, ASA, and TLA on MRI than on plain radiography. In conclusion, the preoperative ASA and TLA on MRI were risk factors associated with ASFs in OTFs treated with PV.

Corrigendum to how to define an osteoporotic vertebral fracture

[This corrects the article DOI: 10.21037/qims.2019.09.10.].

Elderly males with or without existing osteoporotic vertebral fracture have much lower future vertebral fracture risk than elderly females: the MrOS (Hong Kong) year-4 follow-up spine radiograph study

MrOS (Hong Kong)'s year-4 follow-up shows, for subjects at baseline without vertebral deformity (VD) and endplate or/and cortex fracture (ECF), the VD progression/new VD rate during follow-up in males was half of our paired MsOS (Hong Kong) study's results. For those with VD or ECF, the VD progression/new VD was less than one sixth of females' rate.

INTRODUCTION

This study documents MrOS (Hong Kong)'s year-4 follow-up, and the results are compared with the MsOS (Hong Kong) study. Of elderly females with Genant's grade-0, -1, -2, and -3 VD, at year-4 follow-up, 4.6%, 8%, 10.6%, and 28.9% had at least one VD progression or incident VD, respectively.

METHODS

Spine radiographs of 1500 Chinese males with baseline (mean age 71.7 years, range 65-91 years) and year-4 follow-up were evaluated according to Genant's VD criteria and ECF (non-existent, ECF0; or existent, ECF1). Grade-2 VDs were divided into mild (VD2m, 25-34% height loss) and severe (VD2s, 34-40% height loss) subgroups. Study subjects were graded into eight categories: VD0/ECF0, VD1/ECF0, VD2m/ECF0, VD0/ECF1, VD1/ECF1, VD2m/ECF1, VD2s/ECF1, and VD3/ECF1. With an existing VD, a further height loss of ≥ 15% was a VD progression. A new VD incident was a change from grade-0 to grade-2/3, or to grade-1 with ≥ 10% height loss.

RESULTS

Of subjects with Genant's grade-0, 2.05% (25/1219) developed at least one VD progression or/and new VD, while of subjects with Genant's grade-1, -2, and -3 VD, only 2% (3/149), 3.1% (3/96), and 2.8% (1/36) developed at least one VD progression/new VD, respectively. Among the three ECF0 groups, there was a significant difference in new ECF incidence, with VD0/ECF0 being the lowest and VD2m/ECF0 being the highest.

CONCLUSION

VD progression/new VD is much less common in elderly men than in elderly women. Vertebrae with VD had a higher risk of developing ECF.

Underreporting characteristics of osteoporotic vertebral fracture in back pain clinic patients of a tertiary hospital in China

Aim

Osteoporotic vertebral compressive fractures (VCFs) ​are known to be commonly missed in X-rays indicated for pulmonary or heart diseases. In this study, we investigated the underreporting status of VCF in back pain clinic patients when the spine was the focus of interest.

Materials and methods

This is a retrospective analysis of 105 female cases (mean: 72 years, range: 55–93 years) from a tertiary hospital in China (facility A, FA). The patients with back and/or leg pain were referred for a spine X-ray. The images were retrieved and transferred to a central reading facility (facility B, FB), where images were double-read by two readers experienced in evaluating osteoporotic vertebral compressive deformity (VCD)/VCF. A qualitative VCD with <20%, 20–25%, 25–40%, and >40% vertebral body height loss was recorded as minimal, mild, moderate, and severe grades, respectively. A ​VCD coexisted with endplate/cortex fracture (ECF) was VCF. FB readings were considered as the reference.

Results

There were 34 true negative cases where FA and FB had a consensus. In 7 cases with minimal VCD, 3 cases with ECF, and 7 cases with minimal or mild VCFs, the FA readings were false negative. No standalone singular moderate or severe VCD/VCF in a patient was missed in FA's reports. In 25 FA reading positive cases with multiple VCFs, one VCF was missed in 8 cases, more than one VCF was missed in 15 cases, and one additional ECF was missed in 2 cases. In 14 cases, FA and FB had VCF number agreement, with the term ‘vertebral fracture’ was used appropriately in FA reports. In 15 cases, FA and FB had agreement in VCF number; however, the appropriate term ‘vertebral fracture’ was not used in FA reports; instead the terms of ‘compressive change’ or ‘wedging change’ were used. In most VCFs, severity grading was not given in FA. In 13 VCFs where grading was reported, all were marked as ‘mild’, including seven mild VCFs, five moderate VCFs, and even one severe VCF.

Conclusion

Among the patients with VCD/VCF, the false negative rate among was 23.9% (17/71), but the missed cases were all minimal or mild grades. One or more VCFs were missed in 32.4% (23/71) of the cases with multiple VCFs. Appropriate severity grading was not reported for most cases.

The translational potential of this article

The underreporting rate of osteoporotic vertebral compressive fracture in back pain clinic patients in a typical tertiary hospital setting in China compared favorably with literature reports. However, there is a general lack of awareness of vertebral endplate/cortex fracture sign and vertebral fracture severity grading, while minimal and mild VCD with endplate/cortex fracture may have clinical significance. Moreover, after one VCF is spotted in a patient, it is highly advisable to carefully check the whole spine so that multiple VCFs will not be missed.

How to define an osteoporotic vertebral fracture?

A vertebral deformity (VD) is not always a vertebral fracture (VF). Because of lack of a completely satisfactory "gold standard", there is no consensus on the exact definition of a VF. Therefore, it may sometimes be difficult, especially in mild cases, to discriminate the prevalent VF from a non-fracture deformity or short vertebral height (SVH). A combined standardized approach based on qualitative and semiquantitative (SQ) vertebral assessment may be the most option to correctly identify a VD as a VF. However this visual approach for VF identification is subjective, therefore it is mandatory an adequate training and experience of radiologist to reach a good sensitivity and specificity. Vertebral morphometry, objective and reproducible method, could be used only to evaluate the severity of VFs but requires the availability of reference values of vertebral height ratios. There is actually an evidentiary basis for suggesting that a qualitative approach by expert radiologists to morphological vertebral assessment, combined SQ and morphometric methods seem to be the preferred option for the correct diagnosis of VF as endplate or/and cortex fracture (ECF) or severe vertebral height loss.

Osteoporotic vertebral deformity with endplate/cortex fracture is associated with higher further vertebral fracture risk: the Ms. OS (Hong Kong) study results

Compared with vertebrae without deformity, vertebrae with mild/moderate deformity have a higher risk of endplate or/and cortex fracture (ecf). Compared with subjects without ecf, subjects with ecf are at a higher risk of short-term (4-year period) deformity progression and new incident deformity.

INTRODUCTION

The progression and incidence of osteoporotic vertebral deformity/fracture (VD/VF) in elderly Chinese females remain not well documented.

METHODS

Spine radiographs of 1533 Chinese females with baseline and year-4 follow-up (mean age 75.7 years) were evaluated according to Genant's VD criteria and endplate/cortex fracture (non-existent: ecf0 or existent: ecf1). Grade-2 VDs were divided into mild (vd2m, 25-34% height loss) and severe (vd2s, 34-40% height loss) subgroups. According to their VD/VF, subjects were graded into seven categories: vd0/ecf0, vd1/ecf0, vd2m/ecf0, vd1/ecf1, vd2m/ecf1, vd2s/ecf1, and vd3/ecf1. With an existing VD, a further height loss of ≥ 15% was a VD progression. A new incident VD was a change from grade-0 to grade-2/3 or to grade-1 with ≥ 10% height loss.

RESULTS

Of subjects with Genant's grades 0, - 1, - 2, and - 3 VD, at follow-up, 4.6%, 8%, 10.6%, and 28.9% had at least one VD progression or new incident VD respectively. Among the three ecf0 groups, there was no difference in VD progression or new VD; while there was a significant difference in new ecf incidence, with vd0/ecf0 being lowest and vd2m/ecf0 being highest. Vd1/ecf0 and vd2m/ecf0 vertebrae had a higher risk of turning to ecf1 than vd0/ecf0 vertebrae. If vd1/ecf0 and vd2m/ecf0 subjects were combined together (range 20-34% height loss) to compare with vd1/ecf1 and vd2m/ecf1 subjects, the latter had significantly higher VD progression and new VD rates.

CONCLUSION

Vertebrae with grade-1/2 VDs had a higher risk of developing ECF. Subjects with pre-existing ECFs had a higher risk of worsening or new vertebral deformities.