Unilateral vs bilateral hip bone mineral density measurement for the diagnosis of osteoporosis

Side-to-side differences in hip bone mineral density in patients with unilateral hip osteoarthritis

BACKGROUND

Accurately evaluating bone mineral density (BMD) in patients with unilateral hip osteoarthritis (OA) is crucial for diagnosing osteoporosis and selecting implants for hip arthroplasty. Our goal was to measure the BMD differences between sides, examine contributing factors, and identify the optimal side for BMD assessment in these patients.

METHODS

We analyzed 108 women with unilateral hip OA. Bilateral hip BMD was assessed automatically through quantitative CT (QCT) utilizing a validated, deep-learning-based approach. We evaluated BMD variations between the OA and healthy hips across total, neck, and distal regions. To determine their contributions, we analyzed factors, including patient demographics, Crowe classification, Bombelli classification, knee OA status, hip functional score, and gluteal muscle volume and density. Furthermore, we examined how side-to-side BMD differences influenced osteoporosis diagnosis using T-scores based on QCT.

RESULTS

The average BMD on the OA side was 6.9 % lower in the total region, 14.5 % higher in the neck region, and 9.4 % lower in the distal region than on the healthy side. Contributing factors to the reduced BMD in the OA hip included younger age, Bombelli classification (atrophic type), and significant gluteal muscle atrophy. Diagnoses from the OA side revealed lower sensitivity (61 %) than those from the healthy side (88 %).

CONCLUSIONS

Analysis on one side alone yields a more precise osteoporosis diagnosis from the healthy side. Nonetheless, bilateral BMD assessment remains crucial, particularly in younger individuals and those with atrophic OA types. Although based on QCT, our findings support bilateral analysis by dual-energy X-ray absorptiometry for these patients.

Discordance Between Spine-Hip and Paretic-Nonparetic Hip Bone Mineral Density in Hemiplegic Stroke Patients: A Multicenter Retrospective Study

OBJECTIVE

To identify the prevalence and factors associated with T-score discordance between the spine and hip, as well as between the paretic and non-paretic hips in hemiplegic stroke patients, this study investigated bone mineral density (BMD) patterns. Bone loss predominantly affects the paretic hip after a stroke, and typical clinical assessments using dual-energy X-ray absorptiometry (DXA) that scan the lumbar spine (LS) and a single hip may overlook an osteoporosis diagnosis. This oversight could potentially lead to suboptimal treatment for stroke patients.

METHODS

This study was a multicenter retrospective analysis of 540 patients admitted for stroke rehabilitation between October 2014 and February 2022, who underwent DXA of LS and bilateral hips.

RESULTS

The prevalence rates of concordance, low LS discordance, and low hip discordance between the LS and hips were 48.2%, 12.2%, and 39.6%, respectively. The discordance rate between bilateral hips was 17.0%. The paretic side had significantly lower total hip T-scores than the non-paretic side (p<0.001). Notably low paretic hip discordance was more prevalent during the chronic phase. DXA scans of the LS and both hips revealed a 0.7%-0.9% higher major discordance compared to LS and single hip DXA scans. The multivariate analysis revealed a significant correlation between a low paretic hip discordance and cognitive impairment (adjusted odds ratio 0.071, 95% confidence interval 0.931-1.003, p<0.05).

CONCLUSION

Since stroke survivors are at high risk for hip fractures, comprehensive BMD assessments, which include LS and bilateral hips, should be considered for post-stroke osteoporosis care to enhance diagnostic accuracy and timely treatment.

Bilateral hip DXA Reporting: 2023 Official Positions of the International Society for Clinical Densitometry

INTRODUCTION

This position development conference (PDC) Task Force examined the use and reporting of bilateral hip bone mineral density (BMD) measurements. This was deemed appropriate as increased availability of Dual-energy X-ray Absorptiometry (DXA) technology offering bilateral hip measurement resulted in more routine clinical use. The International Society for Clinical Densitometry Official Positions accept bilateral hip BMD measurement for clinical use but currently do not include recommendations for reporting those studies.

METHODS

Four key questions regarding bilateral hip reporting were proposed by the PDC Steering Committee. Relevant literature was identified using PubMed. Questions included whether bilateral hip measurements are appropriate for diagnostic classification or monitoring, as well as which bilateral hip regions of interest should be reported for diagnosis and monitoring. Additionally, the appropriate nomenclature for bilateral hip acquisition was defined.

RESULTS

The literature review demonstrated that bilateral hip measurement is appropriate and diagnostic classification should be based on the lowest T-score at the right or left side femoral neck or total hip; the mean T-score should not be used for diagnostic purposes. Mean bilateral total hip is preferred for BMD monitoring. The terms hip, or total hip were deemed appropriate nomenclature instead of femur or total proximal femur.

CONCLUSION

Bilateral hip acquisition is clinically appropriate and reporting and nomenclature standards are offered herein when a bilateral hip study is acquired. In terms of future research, the impact of discordant hips on diagnosis and monitoring was identified as a significant knowledge gap.

Evaluation of the Relationship between Osteoporosis Parameters in Plain Hip Radiography and DXA Results in 156 Patients at a Single Center in Turkey

BACKGROUND

The aim of the current study is to determine the relationship between osteoporosis findings in plain X-ray and dual-energy X-ray absorptiometry (DXA) measurement results and to create an alternative diagnostic method for osteoporosis without DXA measurement when necessary.

METHODS

DXA values and hip radiographs of 156 patients were retrospectively analyzed. Singh index (SI), Dorr index (DI), cortical thickness index (CTI), and canal-to-calcar ratio (CCR) measurements from both plain hip radiographs were determined by two observers. The correlation of the DXA parameters (hip total T-score, femoral neck T-score, hip total Z-score, hip total bone mineral density [BMD], and femoral neck BMD) and osteoporosis markers on plain hip radiography (SI, DI, CTI, and CCR) was calculated. In addition, patients were evaluated by dividing them into three groups according to the level of their T-scores (normal, osteopenia, and osteoporosis). In addition, cut-off values were calculated for CTI and CCR.

RESULTS

The mean age was 68.27 ± 8.27 (50-85) years. There was a strong correlation between hip total T-score values and SI, DI, and CTI (r = 0.683, -0.667, and 0.632, respectively), and a moderate correlation (r = -0.495) with CCR. When both hips were compared, there were strong correlations between radiographic parameters (r = 0.942 for SI, 0.858 for DI, 0.957 for CTI, and 0.938 for CCR, all with p < 0.001). When patients divided into three groups according to the T-score level were compared in terms of SI, DI, CTI, and CCR, it was found to be directly related to osteoporosis level (all p < 0.001). In the differentiation of osteopenia and osteoporosis, the cut-off values were 50.4 degrees for CTI and 60.3 degrees for CCR.

CONCLUSION

Good correlations between hip total T-score values and SI, DI, CTI, and CCR (r = 0.683, -0.667, 0.632, and -0.495, respectively) indicate that the presence of osteoporosis can be detected by hip radiography findings without DXA.

Quantifying misdiagnosis rates from cross-calibration biases and precision errors in dual-energy X-ray absorptiometry of the femoral neck

BACKGROUND

Dual-energy X-ray absorptiometry (DXA) is an exam that measures areal bone mineral density (aBMD) and is regularly used to diagnose and monitor osteoporosis. Except for exam quality issues such as operator error, the quantitative results of an exam are not modified by a radiologist or other physician. DXA cross-calibration errors can shift diagnoses, conceivably leading to alternate intervention decisions and patient outcomes.

PURPOSE

After identifying and correcting a cross-calibration bias of 3.8% in our two DXA scanners' aBMD measurements, we investigated misdiagnosis rates for given cross-calibration errors in a single patient cohort to determine the impact on patient care and the value of cross-calibration quality control.

METHODS

The studied cohort was 8012 patients of all ages and sexes with femoral neck exams that were scanned on a single DXA unit from October 1, 2018 to March 31, 2021. There were six subcohorts delineated by age and sex, three female groups and three male groups. Data reporting focused on the highest risk subcohort of 2840 females aged 65 or older. The DXA unit had no calibration changes during that time. Only one femoral neck-left or right-was randomly chosen for analysis. Patients with multiple qualifying exams within the time interval had one exam randomly chosen. The proof-of-principle simulation shifted the aBMD values within a range of ±10%, ±8%, ±6%, ±4%, ±3.5%, ±3%, ±2.5%, ±2%, ±1.5%, ±1%, ±0.5%, and 0 (no shift); the cross-calibration shifts were informed by published results and institutional experience. Measurement precision was modeled by randomly sampling a Gaussian distribution characterized by the worst acceptable least significant change (LSC) of 6.9%, with 100 000 samplings for each patient. T-scores were recalculated from the shifted aBMD values, followed by reassigned diagnoses from the World Health Organization's T-score-based scheme.

RESULTS

The unshifted original subcohort of women aged 65 and older had 599 normal diagnoses (21.1% of the cohort), 1784 osteopenia diagnoses (62.8%), and 455 osteoporosis diagnoses (16.1%). Osteoporosis diagnosis rates were highly sensitive to aBMD shifts. At the extrema, a -10% aBMD shift led to +161% osteoporosis cases, and a +10% aBMD shift led to -64.5% osteoporosis cases. Within the more plausible ±4% aBMD error range, the osteoporosis diagnosis rate changed -10.5% per +1% aBMD shift as indicated by linear regression (R²  = 0.98). Except for the men aged 49 years and younger subcohort, the total cohort and five subcohorts had fit line slopes ranging between -9.7% and -12.1% with R² ≥ 0.98. Cross-calibration bias had greater influence for diagnosis count rates compared to measurement precision, that is, LSC.

CONCLUSIONS

These results quantify the degree of misdiagnosis that can occur in a clinically relevant cohort due to cross-calibration bias. In medical practices where patients may be scanned on more than one DXA unit, ensuring cross-calibration quality is a critical and high-value quality control task with direct impact on patient diagnosis and treatment course. The clinical impact and incidence of poor DXA quality control practices, and cross-calibration in particular, should be studied further.

Prevalence of osteoporosis and incidence of related fractures in developed economies in the Asia Pacific region: a systematic review

Robust data on osteoporosis in the Asia Pacific region could improve healthcare decision-making. Osteoporosis affects 10-30% of women aged 40 + , and up to 10% of men in 7 developed economies in Asia Pacific. Fractures affect 500-1000 adults aged 50 + per 100,000 person-years. Policymakers and clinicians must address this problem.

PURPOSE

Osteoporosis and associated fractures result in considerable morbidity, loss of productivity, early mortality, and increased healthcare expenses. Many countries in the Asia Pacific (AP) region, especially middle- and higher-income economies, are faced with aging and increasingly sedentary populations. It is critical to consolidate and analyze the available information on the prevalence and incidence of the disease in these countries.

METHODS

We systematically reviewed articles and gray literature for Australia, China, Hong Kong, Japan, Singapore, South Korea, and Taiwan. We searched PubMed, ScienceDirect, JSTOR, Cochrane, Google Scholar, and other databases for data published 2009-2018. We included articles with prevalence or incidence estimates for adults with osteoporosis or related fractures.

RESULTS

All locations had data available, but of widely varying quantity and quality. Most estimates for osteoporosis prevalence ranged from 10 to 30% for women ages 40 and older, and up to 10% for men. Osteoporotic fracture incidence typically ranged between 500 and 1000 per 100,000 person-years among adults aged 50 and older. Both outcomes typically increased with age and were more common among women.

CONCLUSION

Osteoporosis and associated fractures affect significant portions of the adult population in developed economies in the AP region. Governments and healthcare systems must consider how best to prevent and diagnose osteoporosis, and manage affected individuals, to reduce healthcare costs and mortality associated with fractures.

Establishing a Total Hip T-Score Threshold to Measure Contralateral Hip Bone Mineral Density: Avoiding Missed Diagnosis of Osteoporosis

Bone mineral density (BMD) of the hip is routinely measured unilaterally, but can differ between left and right. This study aimed to establish total hip T-score thresholds for measuring contralateral hip BMD, to avoid missing the diagnosis of osteoporosis. In 4914 participants (2709 females) in the Busselton Healthy Ageing Study, BMD of both hips and lumbar spine (L1-L4) was measured by dual-energy x-ray absorptiometry (DXA) using a GE Lunar Prodigy Pro densitometer. Least significant change (LSC) was calculated according to International Society for Clinical Densitometry recommendations. For participants whose left-right total hip BMD difference exceeded LSC, the 95th percentile of the difference in T-score was calculated, then added to -2.5 (the cut-off for osteoporosis) to derive T-score thresholds for measuring contralateral hip to avoid a missed diagnosis in 95% of individuals. Participant mean age (±SD) was 57.4 ± 5.8 years; total hip T-score was 0.7 ± 0.1 in males and -0.2 ± 1.1 in females. Left and right total hip BMD were highly correlated (r = 0.943 for males, 0.959 for females), but in 56.2% of males and 50.0% of females, the left-right difference exceeded the LSC of 0.026 g/cm². In these participants, the 95th percentile of difference in T-score between two hips was 0.872 in males and 0.742 in females. This gave T-score thresholds for measuring contralateral total hip BMD of -1.6 (males) and -1.8 (females). When total hip T-score is between -1.6 and -2.5 (males), or between -1.8 and -2.5 (females), measuring contralateral hip BMD could avoid a missed diagnosis of osteoporosis.

Dual Hip DXA. Is it Time to Change Standard Protocol?

Previous studies have examined the utility of bilateral DXA hip bone mineral density (BMD) scans. While most studies demonstrate an advantage of bilateral hip scanning, the studies have been limited by size, or have not included simultaneous lumbar spine scans. To analyse the utility of dual hip scans in a clinical environment, a large retrospective study was performed of DXA BMD of both hips, and lumbar spine, in 17,169 individuals assessed at one centre over 10 years. There was no clinically significant difference in the population mean femoral neck BMD of the left vs the right leg (0.878 vs 0.881g/cm2) or total proximal femoral BMD of the left vs the right leg (0.920 vs 0.919g/cm2). There were however discrepancies in individuals between hip t-scores. For the total hip 1,977 (11.5 %) and 147 (0.9 %) of subjects had absolute t score differences ≥ 0.50 or ≥ 1.00. respectively. For the femoral neck 3,320 (19.3%) and 337 (2.0%) of subjects had absolute t score differences ≥ 0.50 or ≥ 1.00. respectively. Of the total 17,169 individuals there were 2,776 subjects with osteoporosis (T≤ -2.5) using the lumbar spine and right hip, compared to 2,834 subjects using the lumbar spine and left hip. Using the lumbar spine and both hips identified 3,214 individuals with osteoporosis. Diagnosis based on use of the lumbar spine and right hip BMD, or lumbar spine and left hip BMD, therefore failed to identify 15.8%, or 13.4%, of osteoporotic subjects respectively. Additional scanning time required was assessed in 40 subjects prospectively. Performing lumbar spine and both hips, compared to lumbar spine and one hip, required an average additional scan time of 55 seconds. The recommendation of best practise for DXA BMD measurements should be reviewed to consider lumbar spine and dual hip DXA as standard of care.

Additive effects of eldecalcitol in poorly responding long-term bisphosphonate treatment for osteoporosis

Objectives

We examined whether eldecalcitol (ELD) provided additive bone mineral density (BMD) and bone turnover marker gains in patients undergoing long-term bisphosphonate (BP) usage, especially in osteoporotic individuals exhibiting a poor response to BPs.

Methods

Forty-two post-menopausal patients with primary osteoporosis and low lumbar BMD (L-BMD) and/or bilateral total hip BMD (H-BMD) values receiving long-term BP treatment were prospectively enrolled. Serum bone alkaline phosphatase (BAP) was measured as a bone formation marker and urinary N-terminal telopeptide of type I collagen (NTX) was assessed as a bone resorption marker. L-BMD, H-BMD, and femoral neck BMD (N-BMD) were recorded before, at the commencement of, and during ELD administration.

Results

BAP and urinary NTX were significantly decreased by BP therapy prior to ELD. ELD addition further significantly decreased the bone turnover markers (both p < 0.01). The mean L-BMD increase rate was 0.2% (p = 0.81) from 2 to 1 years before ELD administration, -0.7% (p = 0.30) during the year before ELD, and 2.9% (p < 0.01) during 1 year of ELD. Similar findings were observed for the mean increase rate of H-BMD, with values of 0.2% (p = 0.55), -0.7% (p < 0.01), and 1.2% (p < 0.01), respectively. The mean N-BMD increase rate was significantly increased after ELD administration (1.1%, p = 0.03) despite no gains by BP therapy alone.

Conclusions

This study suggests that ELD addition may be useful for osteoporotic patients exhibiting a diminished long-term BP therapy response.

Clinical Implications of Hip Flexion in the Measurement of Spinal Bone Mineral Density

The aim of this study was to investigate if differences in leg positioning affect spinal bone mineral density (BMD) measurements and the detection of low bone mass. Subjects included 1039 Japanese patients, 878 women and 161 men (mean ages: 67 and 71 years, respectively). Spinal BMD (L1-4) was measured using dual-energy X-ray absorptiometry (DXA) with patients lying in 2 different positions: (1) supine on the scanning table with hips flexed and knees flexed over a 90° support pad (the standard position) and (2) simply supine (the supine position). Predictive indices were calculated for spinal DXA acquired with patients in the supine position. A BMD T-score of -2.5 or lower was set as the threshold for low bone mass. For the standard and the supine positions during scanning in women, BMDs were 0.911 and 0.915 g/cm(2), respectively; in men, they were 1.117  and 1.124 g/cm(2), respectively. The estimated systematic bias in BMD between the positions was 0.42% (95% confidence interval: 0.24, 0.59; p = 0.009). Random errors in the densitometry measurements for the standard and supine positions were 0.66% and 0.84%, respectively. There was no significant difference between the errors (p= 0.164). The likelihood ratios of a positive and negative test for the detection of low bone mass following supine DXA were 121.0 and 0.066, respectively, compared with results acquired using the standard position. In conclusion, DXA measurements acquired with patients in the supine position slightly overestimated BMD vs the standard position. However, the clinical equivalency between the positioning methods for DXA is preserved to the extent that low bone mass can be reliably detected in the supine position.