Quantification Of Bone Loss Research Articles

Using natural, stable calcium isotopes of human blood to detect and monitor changes in bone mineral balance

We are exploring variations in the Ca isotope composition of blood and urine as a new tool for early diagnosis and monitoring of changes in bone mineral balance for patients suffering from metabolic bone disease, cancers that originate in or metastasize to bone, and for astronauts who spend time in low gravity environments. Blood samples are often collected instead of, or in addition to, urine in clinical settings, so it is useful to know if variations in the Ca isotope composition of blood carry the same information as variations in urine. We found that the Ca isotope composition of blood shifts in the same direction and to the same magnitude (~2partspertenthousand — pptt) as that of urine in response to skeletal unloading during bed rest. However, the Ca isotope composition of blood is lighter than that of urine by 12±2pptt. This offset between blood and urine may result from Ca isotope fractionation occurring in the kidneys. This is the first study to confirm the suspected offset between the Ca isotope composition of blood and urine in humans, to directly quantify its magnitude, and to establish that either blood or urine can be used to detect and quantify bone loss.

Glenoid Diameter Is an Inaccurate Method for Percent Glenoid Bone Loss Quantification: Analysis and Techniques for Improved Accuracy

To compare diameter-based glenoid bone loss quantification with a true geometric calculation for the area of a circular segment. By use of Maxima 12.01.0 mathematics modeling software (Macysma, Boston, MA), the diameter-based glenoid bone loss equation (% Bone loss= [Defect width (w)/Inferior glenoid circle diameter (D)]× 100%) was compared with a true geometric calculation for the area of a circular segment of the glenoid (Wolfram Research, Champaign, IL) rearranged in terms of w and D: Percent bone loss= (100/2π) (2× arccos [1- 2 (w/D)]- sin {2× arccos [1- 2 (w/D)]}). Percent error was calculated by taking the difference between the diameter equation and the true geometric calculation at varying true glenoid defect widths (w) (0% to 50% of diameter). The commonly used diameter equation overestimated true glenoid bone loss at all values of w except at 0% and 50% of the diameter. The mean overestimation error was 3.9% ± 1.9% (range, 0.0% to 5.8%), with the maximum error occurring when w was 20% of the diameter: At this value, w/D× 100% (diameter equation) predicts 20% bone loss when true bone loss is actually 14.2%. Diameter-based glenoid bone loss quantification overestimates true glenoid bone loss, with the maximum error occurring when theorized bone loss is 20%. To address situations for which a diameter-based bone loss quantification method must be performed or to improve the accuracy of surface-area calculations in previous diameter-based bone loss estimations, a corrective factor can be applied. Clinicians quantifying glenoid loss to make treatment decisions should be aware of the measurement methods used in the biomechanical studies on which they are basing their surgical decisions. Diameter-based glenoid bone loss quantification overestimates true glenoid bone loss, with the maximum error occurring when theorized bone loss is 20%, a commonly used threshold forbone grafting.

FRI0063 Changes in Bone Mass over Time in Subjects with Rheumatoid Arthritis: an Observational Study

BackgroundIt is widely accepted that patients with rheumatoid arthritis (RA) lose bone mass more rapidly those without such history over time due to a number of factors including systemic inflammation...

Bariatric Surgery and Bone Loss: Do We Need to Be Concerned?

Despite significant improvement in weight and comorbid conditions, there is growing evidence that bariatric surgery may exert a negative effect on the skeleton. This review has focused on the impact of bariatric surgery on bone health, with the concern that bariatric surgery may increase skeletal fragility and fracture risk by accelerating bone loss. We have highlighted studies evaluating changes in bone metabolism after three commonly performed bariatric procedures including laparoscopic adjustable gastric banding, Roux-en-Y gastric bypass surgery and increasingly popular sleeve gastrectomy. This review has also discussed some of the technical issues faced in measuring bone in obese populations and during dynamic weight loss. There is limited evidence regarding potential mechanisms for the reported observations of increased bone turnover and/or bone loss after bariatric surgery. We have reviewed the evidence surrounding potential factors affecting bone health in bariatric patients such as rapid weight loss per se, nutritional deficiencies, effects of fat-derived adipokines and gut-derived appetite-regulatory hormones. Future prospective long-term cohort studies are needed to define how to quantify bone loss in individuals with obesity, particularly following massive weight loss, and for how long the bone changes continue. These studies will help clarify any negative clinical consequences of these changes, including future fracture risk in this unique group of patients.

Techniques to evaluate glenoid bone loss.

Assessing glenoid morphology as well as quantifying bone loss is critical when treating patients with recurrent anterior glenohumeral instability because this greatly affects surgeons surgical planning. Although many surgeons agree that 3-dimensionally reconstructed computed tomography (3DCT) images with humeral head digitally subtracted has been considered to be a gold standard when assessing glenoid morphology, there are some surgeons who are making an attempt to replace computed tomography with magnetic resonance imaging to reduce cost for imaging studies and avoid possible radiation exposure, and demonstrated that MRI was equally valuable as 3DCT to quantify glenoid bone loss. However, the role of preoperative imaging study is not only quantifying glenoid bone loss but to assess the glenoid shape and morphology to facilitate surgeons stabilizing the shoulder. In this view, 3DCT is the most recommended preoperative imaging study for bony tissue which provides critical and substantial information of the glenoid.

Glenoid Diameter is an Inaccurate Method for Glenoid Bone Loss Quantification (SS-07)

Accuracy in estimating glenoid bone loss is critical for surgical decision making in patients with recurrent shoulder instability. Glenoid bone loss greater than 20-25% indicates that an open procedure may be necessary to reconstitute bone whereas 10-15% bone loss is most commonly managed with arthroscopic techniques. Although diameter-based calculations are broadly used in both arthroscopic and CT scan bone loss estimation methods due to their simplicity, the true accuracy of these means has not been validated.

Quantifying Glenoid Bone Loss in Anterior Shoulder Instability

Background: Glenoid support is critical for stability of the glenohumeral joint. An accepted noninvasive method of quantifying glenoid bone loss does not exist. Purpose: To perform independent evaluations of the reliability and accuracy of standard 2-dimensional (2-D) and 3-dimensional (3-D) computed tomography (CT) measurements of glenoid bone deficiency. Study Design: Descriptive laboratory study. Methods: Two sawbone models were used; one served as a model for 2 anterior glenoid defects and the other for 2 anteroinferior defects. For each scapular model, predefect and defect data were collected for a total of 6 data sets. Each sample underwent 3-D laser scanning followed by CT scanning. Six physicians measured linear indicators of bone loss (defect length and width-to-length ratio) on both 2-D and 3-D CT and quantified bone loss using the glenoid index method on 2-D CT and using the glenoid index, ratio, and Pico methods on 3-D CT. The intraclass correlation coefficient (ICC) was used to assess agreement, and percentage error was used to compare radiographic and true measurements. Results: With use of 2-D CT, the glenoid index and defect length measurements had the least percentage error (−4.13% and 7.68%, respectively); agreement was very good (ICC, .81) for defect length only. With use of 3-D CT, defect length (0.29%) and the Pico1 method (4.93%) had the least percentage error. Agreement was very good for all linear indicators of bone loss (range, .85-.90) and for the ratio linear and Pico surface area methods used to quantify bone loss (range, .84-.98). Overall, 3-D CT results demonstrated better agreement and accuracy compared to 2-D CT. Conclusion: None of the methods assessed in this study using 2-D CT was found to be valid, and therefore, 2-D CT is not recommended for these methods. However, the length of glenoid defects can be reliably and accurately measured on 3-D CT. The Pico and ratio techniques are most reliable; however, the Pico1 method accurately quantifies glenoid bone loss in both the anterior and anteroinferior locations. Future work is required to implement valid imaging techniques of glenoid bone loss into clinical practice. Clinical Relevance: This is one of the only studies to date that has investigated both the reliability and accuracy of multiple indicators and quantification methods that evaluate glenoid bone loss in anterior glenohumeral instability. These data are critical to ensure valid methods are used for preoperative assessment and to determine when a glenoid bone augmentation procedure is indicated.

3-D CT is the most reliable imaging modality when quantifying glenoid bone loss.

Posttraumatic anterior shoulder instability is associated with anterior glenoid bone loss, contributing to recurrence. Accurate preoperative quantification of bone loss is paramount to avoid failure of a soft tissue stabilization procedure as bone reconstruction is recommended for glenoid defects greater than 20% to 27%. We determined whether radiography, MRI, or CT was most reliable to quantify glenoid bone loss in recurrent anterior shoulder instability. Seven intact fresh-frozen human cadaveric shoulders were imaged with radiography, MRI, CT, and three-dimensional (3-D) CT. Three sequential anterior glenoid defects then were created, measured, and the shoulders reimaged after each defect. Defect sizes were less than 12%, 12% to 25%, and 25% to 40%. The gold standard measurement was determined by comparing measurements taken on the cadaver by two surgeons using digital calipers with the measurements determined by using electronic digital calipers on the 3-D CT. This measurement was used for comparison of all estimations by the evaluators. Twelve independent blinded evaluators reviewed the 112 image sets and estimated the percent of glenoid bone loss. Images were scrambled and rereviewed by the same observers 2months later to determine intraobserver reliability. We determined reliability with kappa values. Kappa values between predicted bone loss versus true loss (determined by our gold standard measurements) across all 12 raters for each modality were: 3-D CT, 0.50; CT, 0.40; MRI, 0.27; and radiographs, 0.15. Interobserver agreement (kappa) values were: 3-D CT, 0.54; CT, 0.47; MRI, 0.31; and radiographs, 0.15. The intraobserver agreement (kappa) values were: 3-D CT, 0.59; CT, 0.64; MRI, 0.51; and radiographs, 0.45. Three-dimensional CT was the most reliable imaging modality for predicting glenoid bone loss. Regular CT was the second most reliable and reproducible modality.

Defining the normal acetabular vault in adult males and females using a novel three‐dimensional model

The management and quantification of bone loss is a major challenge in primary and revision total hip replacement. Defining the normal three-dimensional (3D) anatomy of the acetabular vault could aid in assessing pathologic changes and in designing prosthetic joint components. We performed a quantitative assessment of normal 3D acetabular vault structure to define the shape and location of weight-bearing acetabular bone referred to as the vault. Images from 70 normal hip computed tomography images were used to define the 3D acetabular vault anatomy and develop a 3D model. Variation in vault shape was quantified by measuring the distance between every surface point on a subject's hemipelvis and the reference vault. Variation among different hip alignments was assessed using 19 scans from subjects with varus, valgus and dysplastic hip morphologies. The acetabular vault model had 96.6% (95% CI: 91.7-101.5), 97.8% (95% CI: 94.5-101.1) and 96.4% (95% CI: 98.7-94.1) of the surface points within 3 mm of normal male, normal female and abnormal hip specimens, respectively. Comparison of acetabular vault model fit between gender and hip types revealed that it was only significantly different between normal males and normal females (P = 0.0194) and between normal males and dysplastic females (P = 0.0377). A conserved 3D acetabular vault shape and location exists that can accommodate various hip morphologies. Defining a normal vault may increase the precision with which hip pathology can be identified and may also serve as a preoperative assessment tool for planning total hip arthroplasty.

Brief communication: Reevaluating osteoporosis in human ribs: The role of intracortical porosity

Osteoporosis is a major health concern in modern society and is continually being evaluated in past populations by quantifying bone loss. Cortical area measures are commonly used in anthropological analyses to assess bone loss in the ribs, but these values are typically based on endosteal expansion and do not account for intracortical bone loss. The objective of this study is to evaluate the effectiveness of using absolute cortical area, compared to traditional cortical area measures to describe global bone loss in elderly ribs. Transverse sections were prepared from sixth ribs of ten elderly subjects, and bone area measurements were made from 100× magnification composites of each rib for calculation of cortical area (Ct.Ar) and percent cortical area (% C/T). In addition, all areas of intracortical porosity were measured and percent porosity area (% Po.Ar) calculated. Absolute cortical area (Ct.Ar(A)) was calculated by subtracting porosity area from cortical area, and a percent absolute cortical area (% C(A)/T) calculated. ANOVA results reveal significant interindividual variation in percent porosity area (% Po.Ar). Percent cortical area and percent absolute cortical area values were compared and results show a mean difference of 4.08% exists across all subjects, with a range of 1.19-11.73%. This suggests that intracortical porosity is variable and does play a role in age-associated bone loss in the rib. All future investigations of osteoporosis should account for intracortical porosity in bone loss.

Quantification of periarticular demineralization and synovialitis of the hand in rheumatoid arthritis patients

The bone mineral density (BMD) measurement of the hand in rheumatoid arthritis (RA) patients is no standard measurement method as yet. The aim was to contribute to the standardization of the hand BMD measurement, especially of periarticular regions. As results, we found best precision values for the wrist and a significant correlation between hand and spine/femur BMD depending on disease activity and disease duration. This study was conducted to investigate (i) the precision of periarticular hand BMD measuring, (ii) the periarticular demineralization of the hand, (iii) the correlation between periarticular hand BMD and spine/femur BMD, and (iv) the correlation of hand BMD to hand synovitis. A number of 52 RA patients were examined by BMD measurement of the femoral neck, spine, whole hand, metacarpophalangeal (MCP) joints II-V, personal identity profile (PIP) joints II-V, and wrist using dual-energy X-ray absorptiometry (DXA). Synovitis of the hand was examined by ultrasonography and magnetic resonance imaging (MRI). Three subgroups were further analyzed: early RA, established RA with moderate and with high disease activity. Early RA and established RA patients with high disease activity were Followed up after 12 months. We found (1) best precision of BMD measurement for the wrist, (2) BMD in RA significantly reduced if compared to normal controls, (3) a highly significant positive correlation between hand and spine/femur BMD and the power of correlation to depend on disease activity and disease duration (high correlation in RA with moderate disease activity and early RA, very high correlation in RA with high disease activity), (4) a negative correlation between hand BMD and hand synovitis in RA with high disease activity, and (5) a significant reduction of synovitis but no change in hand BMD after 12 months, respectively. This study shows a highly significant correlation between hand BMD and spine/femur BMD in RA patients depending on disease activity and disease duration. We conclude to measure BMD at different sites including hands in order to quantify bone loss in RA patients most properly.

Integrated Imaging Approach to Osteoporosis: State-of-the-Art Review and Update

Osteoporosis is the most common of all metabolic bone disorders. It is characterized by low bone mass and microarchitectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fractures. Because of the increasing aging of the world population, the number of persons affected by osteoporosis is also increasing. Complications related to osteoporosis can create social and economic burdens. For these reasons, the early diagnosis of osteoporosis is crucial. Conventional radiography allows qualitative and semiquantitative evaluation of osteoporosis, whereas other imaging techniques allow quantification of bone loss (eg, dual-energy x-ray absorptiometry and quantitative computed tomography [CT]), assessment for the presence of fractures (morphometry), and the study of bone properties (ultrasonography). In recent years, new imaging modalities such as micro-CT and high-resolution magnetic resonance imaging have been developed in an attempt to help diagnose osteoporosis in its early stages, thereby reducing social and economic costs and preventing patient suffering. The correct diagnosis of osteoporosis results in better management in terms of prevention and adequate pharmacologic or surgical treatment.

Recurrent anterior shoulder instability: accuracy of estimations of glenoid bone loss with computed tomography is insufficient for therapeutic decision-making

To evaluate the reliability of glenoid bone loss estimations based on either axial computed tomography (CT) series or single sagittal ("en face" to glenoid) CT reconstructions, and to assess their accuracy by comparing with actual CT-based bone loss measurements, in patients with anterior glenohumeral instability. In two separate series of patients diagnosed with recurrent anterior glenohumeral instability, glenoid bone loss was estimated on axial CT series and on the most lateral sagittal (en face) glenoid view by two blinded radiologists. Additionally, in the second series of patients, glenoid defects were measured on sagittal CT reconstructions by an independent observer. In both series, larger defects were estimated when based on sagittal CT images compared to axial views. In the second series, mean measured bone loss was 11.5% (SD = 6.0) of the total original glenoid area, with estimations of 9.6% (SD = 7.2) and 7.8% (SD = 4.2) for sagittal and axial views, respectively. Correlations of defect estimations with actual measurements were fair to poor; glenoid defects tended to be underestimated, especially when based on axial views. CT-based estimations of glenoid bone defects are inaccurate. Especially for axial views, there is a high chance of glenoid defect underestimation. When using glenoid bone loss quantification in therapeutic decision-making, measuring the defect instead of estimating is strongly advised.

Standardized Analysis of Mandibular Osteoradionecrosis in a Rat Model

To develop a rat model of mandibular osteoradionecrosis(ORN) that uses novel micro-computed tomography bone volume analysis and detailed histology to provide a more effective, quantifiable, and standardized way to study ORN in vivo. Animal model. Academic medical center. Modifications to our previously published rat model of mandibular ORN were done to develop an ideal protocol consisting of 10 rats (6 experimental and 4 controls) with their left middle mandibular molar removed 7 days after either 20 Gy high dose rate brachytherapy or sham irradiation. Rats were sacrificed 21 days after extraction for landmark defined bone volume and histologic analysis. A standardized method of quantification was achieved in all samples. The radiated group (XRT) had a mean bone volume/total volume (BV/TV) of 13.8% compared to 65.9% for controls (P < .001). There were increases in osteoclasts and fibrosis, decreases in osteoblasts,and less bone in radiated samples with a mean (SD)of 5.91 (3.77) osteoclasts/high-powered field (HPF) and 4.00(1.83) osteoblasts/HPF in XRT samples compared to 1.08(1.08) osteoclasts/HPF and 22.49 (6.00) osteoblasts/HPF for controls (P <.001). Our updated model continues to be clinically analogous to human mandibular ORN and improves the radiologic and histologic analysis of bony defects, providing a method for quantification of bone loss. Further cell-specific staining, including immunohistochemistry, can be used with this model to study potential cellular mechanisms of mandibular ORN and test any future therapeutic options.

Early decrements in bone density after completion of neoadjuvant chemotherapy in pediatric bone sarcoma patients

BackgroundBone mineral density (BMD) accrual during childhood and adolescence is important for attaining peak bone mass. BMD decrements have been reported in survivors of childhood bone sarcomas. However, little is known about the onset and development of bone loss during cancer treatment. The objective of this cross-sectional study was to evaluate BMD in newly diagnosed Ewing's and osteosarcoma patients by means of dual-energy x-ray absorptiometry (DXA) after completion of neoadjuvant chemotherapy.MethodsDXA measurements of the lumbar spine (L2-4), both femora and calcanei were performed perioperatively in 46 children and adolescents (mean age: 14.3 years, range: 8.6-21.5 years). Mean Z-scores, areal BMD (g/cm2), calculated volumetric BMD (g/cm3) and bone mineral content (BMC, g) were determined.ResultsLumbar spine mean Z-score was -0.14 (95% CI: -0.46 to 0.18), areal BMD was 1.016 g/cm2 (95% CI: 0.950 to 1.082) and volumetric BMD was 0.330 g/cm3 (95% CI: 0.314 to 0.347) which is comparable to healthy peers. For patients with a lower extremity tumor (n = 36), the difference between the affected and non-affected femoral neck was 12.1% (95% CI: -16.3 to -7.9) in areal BMD. The reduction of BMD was more pronounced in the calcaneus with a difference between the affected and contralateral side of 21.7% (95% CI: -29.3 to -14.0) for areal BMD. Furthermore, significant correlations for femoral and calcaneal DXA measurements were found with Spearman-rho coefficients ranging from ρ = 0.55 to ρ = 0.80.ConclusionsThe tumor disease located in the lower extremity in combination with offloading recommendations induced diminished BMD values, indicating local osteopenia conditions. However, the results revealed no significant decrements of lumbar spine BMD in pediatric sarcoma patients after completion of neoadjuvant chemotherapy. Nevertheless, it has to be taken into account that bone tumor patients may experience BMD decrements or secondary osteoporosis in later life. Furthermore, the peripheral assessment of BMD in the calcaneus via DXA is a feasible approach to quantify bone loss in the lower extremity in bone sarcoma patients and may serve as an alternative procedure, when the established assessment of femoral BMD is not practicable due to endoprosthetic replacements.

A genome wide linkage scan of metacarpal size and geometry in the Framingham Study

Bone geometry is a significant component of bone strength, and has a clinical utility in predicting fractures and quantifying bone loss. Bone geometry is known to have a substantial genetic component. We performed linkage analysis to identify chromosomal regions governing metacarpal bone geometry. A genome-wide scan (with a set of 615 markers with spacing of approximately 5.7 cM) was performed on 1,702 individuals from 330 extended families of the Framingham Study. Midshaft width was measured and several indices calculated, namely Metacarpal Cortical Thickness (MCT), Cortical Index (MCI), and Section Modulus (MZ), using digitized X-rays of 1,380 participants (men, n = 666, mean age 55.2 yr, women, n = 714, 55.5 yr). Metacarpals 2, 3, and 4 were averaged. Heritability was significant for all indices, ranging from 0.51 to 0.72. Linkage analysis of indices adjusted for age, age(2), and estrogen status in women, identified chromosomal regions 6p21, 9p21, 11q21-q22, and Xq26-Xq27, with LOD scores >2.0. Additional adjustment for smoking, height, and BMI, generally reduced the LOD scores. Finally, bivariate linkage analysis confirmed that a QTL on chr. 6 (51 cM) was shared by midshaft width and MZ (LOD = 2.40, adjusted for all covariates). Neither MCT nor MCI shared linkage loci with width or MZ. In conclusion, we have identified chromosomal regions potentially linked to bone geometry. Genes in these regions may regulate bone geometry via effects on body size. Identification and subsequent characterization of loci for bone geometry can further elucidate the genetic contributions to bone's resistance to stress.

Multimodal Imaging Analysis of Tumor Progression and Bone Resorption in a Murine Cancer Model

This study evaluates the use of multimodal imaging to qualitatively and quantitatively measure tumor progression and bone resorption in a xenotransplanted tumor model of human neuroblastoma. Human neuroblastoma cells expressing a luciferase reporter gene were injected into the femur of nu/nu mice. Tumor progression with and without zoledronic acid treatment was monitored using radiographs, D-luciferin-induced luminescence, micro-computer tomography (CT) and micro-magnetic resonance imaging (MRI). We observed a gradual increase in D-luciferin-based bioluminescence concomitant with detectable osteolytic lesions. Tumor growth was inhibited (P=0.003-0.07) with zoledronic acid treatment. Micro-CT analysis in vivo provided a method to quantify bone loss, and its prevention by zoledronic acid. High-resolution MRI images allowed the observation of tumor cells within the bone marrow cavity, as well as distant metastasis. Multimodal imaging allows to measure tumor growth and bone resorption simultaneously in vivo and also proved useful in the detection distant metastasis.

Bone-Density Changes After Stroke

It has been many years since bone loss and fracture risk were first recognized as serious complications of stroke. Hip fracture is associated with a substantial increase in morbidity and mortality for stroke survivors, and therefore, assessing and maintaining skeletal health after stroke should be an important clinical goal. Recent long-term, prospective studies have illustrated a highly nonuniform pattern of bone changes after stroke. In general, there is significant bone loss on the paretic side, which is greatest in those patients with the most severe functional deficits. In some patients, bone loss in the paretic arm during the first year after stroke is the equivalent of >20 yrs of bone loss in healthy individuals of comparable age. Bone density in the nonparetic upper limb can actually increase after stroke, consistent with an increase in habitual use of the nonparetic hand. Bone density in the paretic lower limb can decrease by >10% in <1 yr, with smaller decreases being typical for the nonparetic lower limb. Despite the recent increase in the number of prospective, longitudinal studies, important questions about bone changes after stroke remain unanswered. Longer-term studies quantifying bone loss for periods of >12 mos poststroke are needed to determine how long excess bone loss continues after stroke. Studies with more subjects and with more varied disability levels are needed to better understand the relationships between functional deficits and bone loss. New metrics are needed to quantify the intensity and duration of physical activity in the upper and lower limbs that are consistent with previous research on the role of mechanical stimuli in bone adaptation. Finally, an assessment of skeletal health and the factors that affect bone quantity and quality should be a standard component in the clinical management of all survivors of stroke.

Accuracy and Consistency of Radiographic Interpretation Among Clinical Instructors in Conjunction with a Training Program

There are inaccuracies and inconsistencies of radiographic interpretation among clinical instructors. The purpose of this investigation was to determine if a training program could improve the accuracy and consistency of instructors' ratings of bone loss. A total of thirty-five clinical instructors consisting of periodontal faculty (periodontists and general dentists), dental hygiene faculty, and periodontal graduate students viewed projected digitized radiographic images and quantified bone loss for twenty-five teeth into four descriptive categories. Ratings of bone loss were made immediately before (pretest) and after (post-test 1) initiation of the training program and then again three months later (post-test 2). Ratings were compared to the correct choice categories as determined by direct measurement using the Schei ruler. Overall agreement with the correct choice improved over time (from 64.5 percent to 85.2 percent) with the greatest change from pretest (64.5 percent) to post-test 1 (76.5 percent). Mean and absolute differences improved in three of the four categories, but worsened in one from pretest to post-test 1. This category returned to its original high value at post-test 2. The greatest improvement in consistency among instructors' ratings was seen in one of the four categories, which was "none" (no bone loss). Extension of the training program may further enhance the accuracy and consistency of instructors' radiographic interpretation.

Skeletal Consequences of Hormone Therapy Discontinuance: A Systematic Review

Although hormone therapy protects against bone loss after menopause, currently it is not recommended once menopausal symptoms have subsided. We reviewed randomized clinical trials to quantify bone loss after stopping hormone therapy and summarize treatment options for women who discontinue hormone treatment. We conducted a search of MEDLINE and EMBASE for randomized, controlled trials measuring bone mineral density (BMD) after hormone therapy discontinuation. Other known published and unpublished data were also included. Eleven studies fulfilled the search criteria. In each, bone loss was rapid after stopping hormone therapy, with BMD declines ranging from 2.3% to 6.2% in the first year. Increases in bone turnover markers also occurred rapidly when hormone therapy was stopped. Limited data addressing treatment after hormone therapy is stopped exist; only 2 studies specifically evaluated therapy to protect bone after hormone discontinuation. Taken together, these 2 studies demonstrate that alendronate produced significant increases relative to placebo in spine, hip, and total body BMD in women with low bone density who had discontinued hormone therapy within the past 3 months, preventing the rapid bone loss seen on discontinuation of hormone therapy. Among treatment options for preventing bone loss on discontinuation of hormone therapy for which randomized clinical trial data are available, alendronate prevented bone loss or increased bone density in postmenopausal women with low bone density. Women who are discontinuing hormone therapy should be counseled about potential bone loss and effective treatment options. Obstetricians & Gynecologists, Family Physicians. After completion of this article, the reader should be able to state that discontinuation of replacement menopausal hormone therapy, which protects against bone loss, is not recommended after menopause symptoms have subsided; recall that it may accelerate bone loss; and explain that there is bone loss preventive treatment for women after discontinuation of hormone therapy.