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PubMed1994

Variation in vertebral height ratios in population studies. European Vertebral Osteoporosis Study Group.

Vertebral height ratios are used to define vertebral deformity in clinical and epidemiologic studies of vertebral osteoporosis. However, few data have been obtained on the variation in these ratios in different populations using standard methods. We examined vertebral morphometric measurements obtained in a population survey from three centers: Malmö (Sweden), Montceau-les-Mines (France), and Graz (Austria), to study the influence of sex and the population center on vertebral height ratios. Radiographs were obtained according to a standardized protocol, and morphometric measurements, anterior height Ha, central height Hc, and posterior height Hp, made in Berlin. The height ratios anterior, Ha/Hp, central, Hc/Hp, posterior I, Hp/Hp', and posterior II, Hp/Hp" (Hp' = posterior height of vertebrae above, Hp" = posterior height of vertebrae below) were calculated for each vertebra from T4 to L4. The mean and standard deviation of these ratios for each sex and each center were derived using a statistical trimming procedure to normalize the distribution. Threshold values for defining grade 1 and grade 2 deformities, wedge, biconcavity, and compression, were calculated using these parameters. Anterior and central vertebral height ratios were smaller in males than females (p < 0.01). There were significant differences between the three centers (p < 0.01) both in the trimmed mean values for anterior and central vertebral height ratios and in the thresholds derived using standard criteria for defining wedge and biconcavity deformity. The data confirm the impression from single-center studies that vertebral height ratios vary between populations and suggest that reference values for vertebral height ratios should be derived separately for males and females within individual populations whenever possible.

Aged↗
PubMed2002

[Vertebral body stenting. A method for repositioning and augmenting vertebral compression fractures].

UNLABELLED: Purpose of the study was to demonstrate the effectiveness of expanding a fractured vertebral body by transpedicular dilatation and stenting. 7 human cadaveric vertebral bodies from L2 to L5 underwent axia compression until a vertebral burst fracture was provoked. Then, by bilateral transpedicular approach, balloon-catheters were introduced, which were armed with stents, usually used for angioplasty. The catheters were inflated with radiolucent fluid and the stents expanded under radiologic control. After expansion, the balloon was deflated and removed, the stents resting inside the vertebral body, holding their inflated shape. Then, the resulting hole was filled with an injectable biodegradable calcium-phosphate. CT-scans were performed after destruction and after expansion. Morphology before and after expansion was judged, using 3-D reconstructions. Vertebral body strength was measured before destruction and after treatment with an Instron testing machine. RESULTS: Vertebral body shape could be restored. Also impressed central parts of the bony endplate could be elevated by using a convergent approach through the pedicles. There was no collapse of the vertebral body after removing the catheter-balloons The vertebral body strength could be restored up to a physiologic level. This procedure gives new perspectives in the treatment either of osteoporotic compression or traumatic vertebral fracture. By using CT-guided technique, it could be performed by a minimally invasive approach percutaneously.

Aged↗
PubMed2002

The diameter of the vertebral canal in dogs in cases of lumbosacral transitional vertebrae or numerical vertebral variations.

From Th1 to L7 midsagittal and interpedicular vertebral canal diameters were measured in macerated spines of 162 dogs to determine, whether the presence of lumbosacral transitional vertebrae or numerical vertebral variations are associated with dislocation of the maximal enlargement of the lumbar vertebral canal. Relative to dogs with a regular number of 27 presacral vertebrae (C7/Th13/L7), the maximal enlargement of the lumbar vertebral canal was more frequently ( P < 0.05) located at vertebra 24 in dogs with 26 presacral vertebrae (C7/Th13/L6), and more frequently at vertebra 25 in dogs with 28 presacral vertebrae (C7/Th13/L8). However, in dogs with 26 presacral vertebrae, maximal agreement in the spinal position of maximal lumbar vertebral canal diameters was achieved relative to dogs with 28 presacral vertebrae by adding one additional thoracic (Th6, 7, or 8) segment. Therefore, the present findings strongly suggest that relative to the regular (C7/Th13/L7) condition, decrease in the number of presacral vertebrae (C7/Th13/L6) is associated with incorporation of a midthoracic segment, whereas increase in the number of presacral vertebrae (C7/Th13/L8) is not related to the presence of an additional vertebral segment. When using Th1 as landmark, the difference in the position of the maximal enlargement of the lumbar vertebral canal between dogs with 26 and dogs with 28 presacral vertebrae in average was only one segment. It is known from previous reports that the maximal enlargement of the lumbar vertebral canal corresponds with the maximal enlargement of the lumbar spinal cord. When using S1 or the transitional vertebra as the landmark for determination of the appropriate site for subarachnoid cannulation, this site is expected to range within the same limits regardless of the vertebral formula.

Animals↗
PubMed2006

Strontium ranelate: vertebral and non-vertebral fracture risk reduction.

Fractures are common at the spine and hip, but at least half the morbidity and mortality of fractures in the community come from fractures that involve other sites. Over half of all fractures arise in individuals without osteoporosis, whereas the highest risk group for fractures are individuals over 80 years of age. Reducing the burden of fractures should thus include an assessment of drug efficacy against all fractures in a wide range of individuals. For vertebral fractures, in the phase III Spinal Osteoporosis Therapeutic Intervention study of 1649 postmenopausal women with osteoporosis, 2 g strontium ranelate a day produced a risk reduction of 49% in the first year and 41% during 3 years. In the TReatment Of Peripheral OSteoporosis study, which was designed to examine the effect of strontium ranelate on non-vertebral fractures, of the 5091 patients, 3640 had spine X-rays. The vertebral fracture risk reduction was 45% at one year and 39% over 3 years. In a preplanned pooling of the above two studies, 1170 patients had vertebral osteopenia. Strontium ranelate reduced the risk of vertebral fracture in 3 years by 40% in these patients. In 409 patients with lumbar or femoral neck osteopenia, strontium ranelate reduced the risk of vertebral fractures by 62% over 3 years. In the pre-planned pooling of data from the two studies, in 1488 women aged between 80 and 100 years (mean age 84 +/- 3 years), the risk of vertebral fractures was reduced in one year by 59% and by 32% over 3 years. For non-vertebral fractures, in the TReatment Of Peripheral OSteoporosis study, treatment for 3 years reduced the fracture risk by 16%, and by 19% for major fragility fractures. In a post-hoc analysis of 1977 women at high risk of hip fracture (aged > or = 74 years and with a femoral neck bone mineral density T-score < or = -2.4) the hip fracture risk was reduced by 36%. In patients aged 80 and over in the pre-planned pooling of data from the two studies, the risk of an incident non-vertebral fracture was reduced by 41% in the first year and by 31% over 3 years. Strontium ranelate, a new anti-osteoporosis agent, has a broad range of antifracture efficacy.

Aged↗
PubMed2002

The association between iliocostal distance and the number of vertebral and non-vertebral fractures in women and men registered in the Canadian Database For Osteoporosis and Osteopenia (CANDOO).

BACKGROUND: The identification of new methods of evaluating patients with osteoporotic fracture should focus on their usefulness in clinical situations such that they are easily measured and applicable to all patients. Thus, the purpose of this study was to examine the association between iliocostal distance and vertebral and non-vertebral fractures in patients seen in a clinical setting. METHODS: Patient data were obtained from the Canadian Database of Osteoporosis and Osteopenia (CANDOO). A total of 549 patients including 508 women and 41 men participated in this cross-sectional study. There were 142 women and 18 men with prevalent vertebral fractures, and 185 women and 21 men with prevalent non-vertebral fractures. RESULTS: In women multivariable regression analysis showed that iliocostal distance was negatively associated with the number of vertebral fractures (-0.18, CI: -0.27, -0.09; adjusted for bone mineral density at the Ward's triangle, epilepsy, cerebrovascular disease, inflammatory bowel disease, etidronate use, and calcium supplement use) and for the number of non-vertebral fractures (-0.09, CI: -0.15, -0.03; adjusted for bone mineral density at the trochanter, cerebrovascular disease, inflammatory bowel disease, and etidronate use). However, in men, multivariable regression analysis did not demonstrate a significant association between iliocostal distance and the number of vertebral and non-vertebral fractures. CONCLUSIONS: The examination of iliocostal distance may be a useful clinical tool for assessment of the possibility of vertebral fractures. The identification of high-risk patients is important to effectively use the growing number of available osteoporosis therapies.

Journal Article↗
PubMed2005

Vertebral deformities identified by vertebral fracture assessment: associations with clinical characteristics and bone mineral density.

Whether vertebral fractures identified on radiographs are painful or not, they are associated with increased morbidity and mortality. Vertebral fractures on X-rays correlate with low bone mineral density (BMD) at the spine and hip in addition to several clinical characteristics. Evidence suggests that vertebral deformities detected by X-ray and by vertebral fracture assessment (VFA) show good agreement. We examined the relationship between VFA-detected vertebral deformities and patient characteristics as well as BMD by analyzing the records of 432 patients who had undergone dual-energy X-ray absorptiometry (DXA) scans with VFA. Patients' demographic data and T-scores were obtained from patient questionnaires and DXA scans. We categorized vertebral deformities by type and severity. Patients with vertebral deformities were significantly older and more likely to report a history of fracture after childhood. Significantly more estrogen use was reported in patients without deformity. Those with deformities had significantly lower T-scores at the femoral neck and total hip but not at the spine. Increased severity and number of deformities correlated with lower T-scores at the total hip and femoral neck but not the spine. In conclusion, vertebral deformities detected by VFA, like those on X-ray, correlate with both clinical characteristics and reduced bone mass at the hip. These relationships, in addition to rapid performance, convenience, and minimal radiation exposure, indicate VFA-detected vertebral deformities are a valuable adjunct in identifying patients in need of additional evaluation and treatment.

Absorptiometry, Photon↗
PubMed1995

Risk of vertebral fractures in men: relationship to mineral density of the vertebral body.

OBJECTIVE: Vertebral fracture is the most frequent manifestation of osteoporosis in women. Because there is a lack of information about bone density and the occurrence of fractures in men with osteoporosis, we evaluated the relationship between vertebral fractures and spinal bone mineral density (BMD) to determine if there is a threshold of BMD below which fractures are likely to occur. SUBJECTS AND METHODS: Radiographs of the spine and BMD measurements of the lumbar spine as measured by quantitative CT were obtained in 201 men 21-86 years old (mean age, 68 +/- 4 years) who were referred consecutively for osteoporosis screening. Radiographs were interpreted for the presence or absence of vertebral fractures. The probability of fractures was determined after classifying the patients into subgroups according to their quantitative CT values. The relationship of spinal bone mass to spinal fracture was examined by both logistic regression and receiver operating characteristic (ROC) analysis. RESULTS: Seventy-one patients were classified as having definite vertebral compression fractures. Spinal BMD was 132 +/- 34 mg/ml for the 130 men without vertebral fractures and 75 +/- 22 mg/ml for the 71 men with vertebral fractures (p < .001). The number of fractures per patient and the BMD were negatively correlated (r = -0.71, p < 0.0001). When a BMD of 100 mg/ml was given as a fracture threshold, 15% of the patients without fractures were below this value and 14% of the patients with fractures were above this threshold. Quantifying the overlap between values from patients with and without fractures by ROC analysis, the value of 100 mg/ml gave a sensitivity of 86%. Logistic regression showed 105 mg/ml as the most discriminate value, resulting in a sensitivity of 90%. Logistic regression analysis of the predicted fracture probability also indicated that age does not significantly influence the regression curve. CONCLUSION: We found that direct quantitative CT measurement of the BMD of the vertebral body is a highly efficient approach to distinguish men without vertebral fractures from those with fractures. Thus, a fracture-threshold concept could provide a quantitative criterion to identify men at high risk for vertebral fractures.

Adult↗
PubMed1987

The treatment of primary vertebral tumors by radical resection and prosthetic vertebral replacement.

The basic principles for the treatment of primary vertebral tumors include radical resection of the tumor, insertion of a prosthetic vertebral body, and bone grafting within and around the prosthetic vertebral body. Since 1970, the authors have treated 12 cases with this procedure. In order to improve the vertebral prosthesis, 94 dried adult vertebral column specimens were studied. The anterior cortex of each vertebral body was thicker than the posterior cortex. The thickness of the anterior cortex of the dorsolumbar vertebral bodies progressively increases from the proximal to caudal vertebra. The lower lumbar vertebrae are therefore almost twice as thick as the upper dorsal vertebrae. The cortices of the vertebral bodies, especially the anterior cortex, serve as a strut against the pressure of the prosthesis. Four types of prostheses were used. The Type 1 prosthesis failed to take into account the anatomic features of the dorsolumbar vertebral bodies in cross section. Types 2, 3, and 4 are modified versions with specific indications for their use.

Adult↗
PubMed1998

The effects of x-axis vertebral translation on projected y-axis vertebral rotation.

BACKGROUND: Few studies have quantified the projection/distortion errors that occur in anteroposterior (AP) radiographs. OBJECTIVES: To quantify the projection/distortion errors on AP radiographs caused by lateral translation of the vertebrae. To demonstrate the effect of vertebral shape on projection errors. STUDY DESIGN: Three models of increasing complexity were constructed to document the distortion. Model 1 consisted of three metal pins embedded in a piece of metal tubing that was X-rayed in three positions. Model 2, a simple model of the X-ray beam mounted on a wooden platform, allowed for translation of a vertebral model in a simulated X-ray beam and the measurement of projected points of contact between the model and rays of the simulated beam. Model 3 is a computer simulation of the X-ray beam in which a vertebral model was translated laterally to varying locations. The projected points of contact between the simulated rays and the vertebral body margins and lamina junction were measured. Model 3 also showed that vertebral body shape has a large effect on the projected axial rotation. Two other simple models were created and discussed in relation to shape-dependent projection errors. RESULTS: X-axis translation results in projected y-axis rotation. Increasing magnitudes of x-axis vertebral translation results in increasing magnitudes of projected y-axis vertebral rotation. The projected rotation is also influenced by vertebral shape. CONCLUSION: We have shown that three-dimensional lateral translation projects as axial rotation on the AP radiograph. Projection error is largely influenced by the shape of the object and by the increasing obliquity of the rays of the X-ray beam. This would seemingly create confusion and invalidate spinal listings of vertebral position obtained from the AP radiographic image.

Axis, Cervical Vertebra↗
PubMed1997

The influence of alcohol consumption on the risk of vertebral deformity. European Vertebral Osteoporosis Study Group.

The influence of alcohol consumption on the risk of osteoporosis is not well established. The aim of this study was to determine the relationship between frequency of alcohol consumption and the risk of vertebral deformity across different European populations. A population survey method was used. Men and women aged 50 years and over were recruited from population-based sampling frames in 36 centres from 19 European countries. Subjects were invited to attend by letter of invitation for an interviewer-administered questionnaire and lateral spinal radiographs. Vertebral deformity was defined morphometrically using the McCloskey-Kanis method. Data from 14237 individuals were available for this analysis. Alcohol consumption was compared between the 809 men and 884 women with vertebral deformity and the 5905 men and 6639 women without vertebral deformity. The frequency of alcohol intake was greater in men than women. Overall, there was no detectable association between frequency of alcohol intake and vertebral deformity in either men or women. Stratification by age showed that women 65 years and over who took alcohol on more than 5 days per week had a reduced risk of vertebral deformity compared with those taking alcohol less than once per week. This protection was most obvious after adjusting for age, centre, body mass index, smoking, current level of physical activity and previous fractures (odds ratio [OR] = 0.65; 95% confidence intervals [CI] = 0.43, 0.99). There was a smaller and non-significant protective effect amongst men aged 65 years and over and this was most apparent amongst moderately frequent drinkers (1-4 days per week) (OR = 0.81; 95% CI = 0.62, 1.08). There was no association between the occurrence of vertebral deformity and frequency of alcohol consumption in younger men and women. Overall, the effects of the frequency of alcohol consumption on vertebral deformity were modest. In older women, regular consumption on more than 5 days per week is associated with a reduced risk. Further, prospective data are required to confirm these findings. It is also necessary to investigate, in terms of amount of alcohol consumed, at what level the benefits of regular intake are obviated by the increased risks from alcohol excess.

Aged↗
PubMed1993

Comparison of the radiographic vertebral trabecular pattern with the vertebral fracture prevalence and spinal bone density.

Spinal bone densitometry allows accurate and precise measurement of the severity of bone loss. Where densitometry is not yet available medical practitioners have to continue to rely on clinical radiography. Since the grey levels of the radiographic image are highly inaccurate we studied the radiographic vertebral trabecular pattern for its suitability as a semiquantitative assessment of vertebral bone loss. We defined four vertebral trabecular pattern indices (VTPI 4 = normal, VTPI 1 = severe bone loss) and tested these for correlations with the prevalence of vertebral fractures, and with spinal and hip bone mineral density measured by dual-energy X-ray absorptiometry (DXA). We found negative correlations between VTPI and the percentage of patients with vertebral fractures (p = 0.0001), between VTPI and the number of vertebral fractures per patient (r = 0.606, p = 0.001) and between VTPI and the severity of vertebral fractures, and a positive correlation between VTPI and spinal (r2 = 0.556, p = 0.0001) and hip DXA values (r2 = 0.315, p = 0.0001). We conclude that the vertebral trabecular pattern index can be used to assess the severity of spinal bone loss when a bone densitometer is not available.

Absorptiometry, Photon↗
PubMed2007

[An improved vertebral body replacement for the thoracolumbar spine. A biomechanical in vitro test on human lumbar vertebral bodies].

BACKGROUND: In recent years, the use of expandable titanium cages for vertebral body replacement in the thoracolumbar spine has been well established for the treatment of tumors, unstable traumatic lesions, or posttraumatic deformity. Collapse of the implant into the vertebral body remains a point of concern. A biomechanical compression test was designed to assess implant subsidence for a newly developed prototype for vertebral body replacement in the thoracolumbar spine using human cadaveric lumbar vertebrae. The objective of this study was to compare the compressive performance of a new expandable cage with modified end-plate design with three commonly available expandable cages for vertebral body replacement. MATERIALS AND METHODS: The compressive strengths at the implant-vertebral body interface were measured via axial loading of the new prototype (Synex II) in comparison with three different expandable titanium cages: Synex I (Synthes), Obelisc (Ulrich Medical) and X-Tenz (DePuy Spine). Twenty-four intact, fresh frozen human lumbar vertebrae (L1-L4) were distributed into four identical groups according to BMD (determined by quantitative computed tomography) and the vertebral level. Specimens were loaded in the craniocaudal direction with a material testing machine at a constant speed of 5 mm/min. Load displacement curves were continuously recorded for each specimen until failure (diminishment of compressive force (F)/obvious implant migration through the vertebral body endplate). One-way analysis of variance and post-hoc tests (Bonferroni) were applied to detect differences at 1, 2, 3, 4 mm displacement (F1-4 mm), and Fmax between implant groups. RESULTS: The four expandable cages did not show statistically significant biomechanical differences in terms of maximum compression force (Fmax) until failure: Synex II (1,782 N/4.7 mm); Synex I (1,645 N/4.7 mm); Obelisc (1,314 N/4.2 mm); X-Tenz (1,470 N/6.9 mm). However, the mean compression force until 4 mm displacement (F1-4 mm: 300-1,600 N) was highest for Synex II. The difference at 2 mm displacement was significant (p=0.028) between Synex II (F2 mm=879 N) and X-Tenz (F2 mm=339 N). CONCLUSION: The modified endplate design of the new prototype was found to improve its compressive performance under constrained uniaxial loading conditions at the implant-bone interface. The improved compressive behaviour of the new implant might help to reduce the risk of implant subsidence and collapse into the vertebral body in vivo.

Aged↗
PubMed1998

Measurements of vertebral shape by radiographic morphometry: sex differences and relationships with vertebral level and lumbar lordosis.

OBJECTIVE: To examine sex-related and vertebral-level-specific differences in vertebral shape and to investigate the relationships between the lumbar lordosis angle and vertebral morphology. DESIGN AND PATIENTS: Lateral thoracic and lumbar spine radiographs were obtained with a standardized protocol in 142 healthy men and 198 healthy women over 50 years old. Anterior (Ha), central (Hc) and posterior (Hp) heights of each vertebra from T4 to L4 were measured using a digitizing technique, and the Ha/Hp and Hc/Hp ratios were calculated. The lumbar lordosis angle was measured on the lateral lumbar spine radiographs. RESULTS: Ha/Hp and Hc/Hp ratios were smaller in men than women by 1.8% and 0.7%, respectively, and these ratios varied with vertebral level. Significant correlations were found between vertebral shape and the lumbar lordosis angle. CONCLUSIONS: These results demonstrate that vertebral shape varies significantly with sex, vertebral level and lumbar lordosis angle. Awareness of these relationships may help prevent misdiagnosis in clinical vertebral morphometry.

Aged↗
PubMed1993

The epidemiology of vertebral fractures. European Vertebral Osteoporosis Study Group.

Vertebral fractures are recognised as a hallmark of osteoporosis, yet little is known of their epidemiology. This deficiency limits accurate characterisation of the public health importance of osteoporosis. Assessment of the impact of vertebral fractures has been hampered by the absence of formal criteria for identifying fractures on a thoracolumbar radiograph. Initial methods relying upon subjective radiological assessments have given way to morphometric measurements of vertebral heights, with deformities defined according to various algorithms. These methods have been used in a series of studies performed in Rochester, MN, to determine the incidence, outcome, and time trends of vertebral deformities. The results suggest a prevalence rate of vertebral deformity of 25.3 per 100 Rochester women aged 50 years and over (95% CI, 22.3-28.2), with an estimated incidence of 17.8 per 1,000 person-years. The incidence of clinically diagnosed vertebral fractures among women in the same population was 5.3 per 1,000 person-years, suggesting that around 30% of such deformities in women receive clinical attention. Morphometric measurement on the radiographs of women with clinically diagnosed fractures revealed that 80% had grade 2 ( > 4 SD) deformities. Comparable data on the occurrence and health impact of vertebral deformities throughout Europe are urgently required. The European Vertebral Osteoporosis Study (EVOS) is a multicentre epidemiological study that aims to address this issue. It is designed as a radiographic prevalence study in 34 European centres.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed2006

Diagnosis of vertebral fractures by vertebral fracture assessment.

Vertebral fractures are independent risk factors for both vertebral and peripheral fractures and only one-third of these fractures come to clinical attention. Vertebral fracture assessment (VFA) is a radiographic method using dual X-ray absorptiometry (DXA) to assess vertebral deformities during bone density measurement. We performed VFA of the spine from T4 to L5 on a Delphi W device (Hologic, Bedford, MA) in 136 postmenopausal patients (69+/-10 yr). These patients also had X-rays of the thoracic and lumbar spine. VFA was independently compared with X-rays by two rheumatologists, for the diagnosis of vertebral fractures at both the patient and vertebral levels. Using X-rays, 61 patients (45%) had at least one vertebral fracture. The percentage of unreadable vertebrae was 1% and 12.4% on X-rays and VFA, respectively (p<0.0001). At the patient level, VFA allowed to diagnose if the patient had no fracture or had at least one fracture in 74% of patients. In 11.2% of cases, VFA misclassified the patients. At the vertebral level, diagnostic efficacy of VFA as compared with X-rays was 97%. Concordance between both observers was good (kappa-score=0.69). We designed an algorithm for decision of performing X-rays in postmenopausal women: Using results of VFA would avoid X-rays in 32% of our patients. VFA is a reliable technique with low radiation, and is easily and rapidly applicable during bone density measurement by DXA, which could improve management of osteoporotic patients.

Absorptiometry, Photon↗
PubMed1995

Prediction of thoracic and lumbar vertebral body compressive strength: correlations with bone mineral density and vertebral region.

The bone density of thoracolumbar vertebral columns (T1 to L5) from 18 individuals was measured using quantitative computed tomography and dual energy x-ray absorptiometry. Three hundred six isolated vertebral bodies were tested in a materials test device to determine their compressive strength. Between T1 and L5 the mean segmental increase in bone mineral content was 0.3 g, while the corresponding mean decrease in trabecular density was 4.7 HU. Midvertebral body cross-sectional area increased by an average of 46 mm2 per segment and the mean segmental increase in compressive strength was 0.17 kN. Compressive strength was significantly correlated with bone mineral density measured with dual energy x-ray absorptiometry (r = 0.86). Vertebral trabecular density samples measured with quantitative computed tomography were poorly correlated with compressive strength (r = 0.28); however, this was improved when the trabecular density was multiplied by the midvertebral body cross-sectional area (r = 0.83). This study provides information concerning the relationships between density and mechanical properties of all thoracic and lumbar vertebral bodies across a wide age range. While the load-bearing capacity of the vertebral bodies is largely dependent on their geometry and bone density, this relationship has been only extensively tested for the lumbar spine. This study extends these observations over the lumbar and thoracic regions to provide a comprehensive analysis of the strength characteristics of each vertebral body. This is particularly important given the paucity of data on the thoracic spine where age-related vertebral fractures predominate. These data provide a basis for the development of models to predict the potential for thoracolumbar fractures in the elderly vertebral column.

Absorptiometry, Photon↗
PubMed2003

The impact of incident vertebral and non-vertebral fragility fractures on health-related quality of life in established postmenopausal osteoporosis: results from the teriparatide randomized, placebo-controlled trial in postmenopausal women.

OBJECTIVE: To report the combined impact of both vertebral and non-vertebral fractures on decreased health-related quality of life (HRQOL) in postmenopausal women (mean age 70.7) with osteoporosis who participated in a clinical trial to examine the anti-fracture efficacy of teriparatide [rhPTH(1-34)] injection. METHODS: Patients were randomly assigned to 1 of 3 study arms: placebo, 20 micro g or 40 micro g of teriparatide by daily self-injection. All patients received daily calcium (1000 mg) and vitamin D (400-1200 U) supplements. Patients were followed for a median of 21 months. Incident vertebral fractures were assessed by lateral spinal radiograph. Incident non-vertebral fractures were ascertained by patient self-report and verified by a review of radiological reports. HRQOL was assessed at baseline and annually until study termination using the Osteoporosis Assessment Questionnaire (OPAQ), a validated disease-targeted instrument. RESULTS: Of the 365 women in the HRQOL sub-study, 53 had an incident vertebral or non-vertebral fracture during the study period. Compared to women without incident fractures, women who fractured reported significant declines in physical functioning, emotional status, and symptoms (all p < 0.05). Similarly, when analysis was limited to patients with significant loss in HRQOL, patients with incident fracture accounted for a greater proportion of those patients with decreased physical function, emotional status, and increased symptoms (all p < 0.05). CONCLUSION: Our results confirm and extend previous findings to show that a composite endpoint of incident vertebral and non-vertebral fractures in women with postmenopausal osteoporosis was associated with significant decreases in HRQOL.

Aged↗
PubMed1986

The origin and evolution of vertebrate pattern and form--a theory of vertebrate development by preformation based on the genetic molecular shape.

A new hypothesis is presented to explain the origin of vertebrate form and the guiding mechanism by which embryological development occurs. The hypothesis is based on the observation which is demonstrated, that both vertebrate form and embryological development follow a pattern which correlates with the shapes formed by a spiral as it unfolds. The fact that the DNA molecule which carries the genetic information for embryological development, also has a helical structure, has suggested the hypothesis, that vertebrate form and its development are related to the molecular shape of the genetic material. A theoretical vertebrate genetic molecular structure is proposed and it is demonstrated how this structure by "unfolding", as growth occurs, (the mechanism for which is suggested) provides an accurate prepattern and a template for vertebrate embryological development and vertebrate form. Evolutionary implications follow, which question the Neo-Darwinian synthesis. These are firstly, that the vertebrate pattern is not the result of random genetic variations and natural selection, but owes its origin to a spiral pattern, possibly that of DNA. Secondly, that progressive changes occurring in the shape of the genetic molecule provide an explanation and a mechanism for the evolution of species; a concept which is demonstrated.

Animals↗