Journal of Clinical Densitometry最新文献

Purpose/Aims

To evaluate Intraoperative Physician Assessment (IPA) during total hip arthroplasty (THA) as a quantitative measure of bone status based on tactile assessment. IPA was compared to DXA-measured bone mineral density (BMD), 3D-Shaper parameters, and radiographic indices to assess its validity for evaluating bone status.

Rationale/Background

The International Society for Clinical Densitometry (ISCD) Official Positions acknowledge the orthopedic surgeons’ ability to assess bone intraoperatively and recommend bone assessment for patients with poor bone quality. Currently, there is no validated method to quantify bone status intraoperatively and correlate it with DXA-parameters. This study sought to fill that void.

Methods

A retrospective analysis identified patients undergoing primary THA who had IPA recorded in the operative report and a DXA within 2 years prior to surgery. Patients were excluded if they had prior surgery on the involved hip. 60 patients (64 hips) operated on by 2 fellowship-trained arthroplasty surgeons were included. Intraoperatively, surgeons subjectively assessed bone quality on a 5-point scale based on tactile feedback. This scale defined 1 as excellent and 5 as poor, as noted in Table 1. IPA score was compared to DXA BMD and T-score, 3D Shaper measurements, WHO classification, FRAX scores, radiographic Dorr classification and Cortical Index. IPA was correlated with bone parameters using the Pearson method for continuous variables and Spearman method for ordinal variables.

Results

Mean (SD) patient age and BMI were 69.1 (8.5) years and 27.7 (5.9) kg/m2 respectively; 54 (84%) were female. Patient demographic data and bone parameters were similar between surgeons. Mean IPA was 2.95 ± 0.98 with no difference between surgeons (p = 0.121). There was a moderate correlation between IPA score and total hip BMD (r = 0.386, p = 0.002) and 3D shaper measurements, including trabecular volumetric BMD (r = -0.326, p = 0.010), cortical surface BMD (r = -0.347, p = 0.006), and cortical thickness (r = -0.381, p = 0.002). There was a strong correlation (all p < 0.001) between IPA score and lowest T-score (r = -0.485), WHO classification (r = 0.528), and FRAX major and hip fracture scores (r = 0.501, 0.622). All patients with below average or poor IPA score had osteopenia or osteoporosis by DXA.

Implications

IPA during THA is a simple, valuable tool for quantifying bone status based on tactile feedback. This information can be used to identify patients with poor bone quality that may benefit from bone health evaluation and treatment.

Purpose/Aims

To assess reliability of lumbar vertebral body computed tomography (CT) attenuation measurement between different observers.

Rationale/Background

The International Society for Clinical Densitometry (ISCD) guidelines for DXA interpretation include assessment of “opportunistic CT” as a surrogate for DXA scan using L1 vertebral body attenuation, with threshold >150 and < 100 Hounsfield units (HU) estimating the likelihood of normal bone density and osteoporosis, respectively. ISCD guidelines include precision analysis of DXA, but there are no formal guidelines for assessing precision error when assessing bone mineral density (BMD) by CT attenuation of lumbar vertebral body. Measurement of precision have been published and we sought to determine inter-rater reliability and to assess precision by test-retest of the same patient.

Methods

Utilizing Visage PACS to view CT images, six observers each measured CT attenuation of L1 and L5 vertebral bodies of the same set of 31 separate CT scans. Measurements were performed as previously described.3 Average HU within an elliptical region of interest (ROI) of the L1 and L5 vertebral bodies were recorded for each measurement, as well as L1 and L5 ROI area. Intra-class correlation (ICC) was calculated for each of these variables, with >0.9 indicating excellent agreement, 0.75-0.9 indicating good agreement, 0.5-0.75 indicating moderate agreement, and < 0.5 indicating poor agreement. ICC was calculated of L1 attenuation measured by a single observer on a separate set of 12 patients with CT scans done within 30 days of each other. Additionally we calculated root mean square–coefficient of variation (RMS-CV) of L1 vertebral body attenuation on this set of 12 patients.

Results

ICC of L1 attenuation and L5 attenuation were 0.94 and 0.92, respectively, indicating excellent agreement between observers. ICC of ROI areas at L1 and L5 ROI were 0.04 and 0.03, respectively, indicating poor agreement (Table 1). ICC of L1 CT attenuation on repeat scans within 30 days by a single observer was 0.97, indicating excellent agreement between two readings . Root mean square-SD was 14.6 HU. Least significant change was 40.4 HU. Percent coefficient of variation was 34.6.

Implications

This study demonstrates that measurement of CT attenuation at L1 and L5 between different observers is reliable while area of region of interest at L1 and L5 between observers showed poor agreement. In test-retest of scans performed within 30 days on the same patient, a short time period in which little change is expected, measurement of CT attenuation also showed excellent agreement.

Purpose/Aims

To compare bone mineral density (BMD) precision of knee custom regions of interest (ROI) with and without total knee arthroplasty (TKA).

Rationale/Background

TKA is a common procedure that results in 10 to 15% BMD loss at the distal femur. This could contribute to complications such as periprosthetic fracture, especially if osteoporosis is present at the time of TKA. Prior work supports measuring BMD around the knee using custom ROIs, this study investigates precision error of such an approach.

Methods

Thirty participants from a study evaluating BMD pre- and post-TKA had duplicate posteroanterior (PA) and lateral (LAT) scans in TKA and non-TKA knees with repositioning between. Scans were acquired on a Lunar iDXA with the orthopedic knee feature (GE enCORE software v18). Custom ROIs were manually placed on PA and LAT scans at the distal femur condyle (ROI 1), metaphysis (ROI 2) and shaft (ROI 3), and the proximal tibia (ROI 4) and tibial shaft (ROI 5) (Figure 1). The prosthesis was identified as artifact by the software. Precision error was calculated using the ISCD Advanced Precision Calculator and differences between TKA vs non-TKA legs were assessed by F-test.

Results

Study participants (n = 30; 6M, 24F) with mean (SD) age and BMI of 69.2 (6.5) years and 31.6 ± 4.9 kg/m2 respectively were included. Precision at various ROIs (Table 1) on non-TKA legs ranged from 1.2 - 3.8% on PA and 2.5 – 5.6% on LAT projections. Similarly, TKA leg ROI %CV ranged from 1.5 - 5.4% and 1.0 – 4.1% on PA and LAT respectively. PA precision differed (p < 0.001) between TKA and non-TKA legs at the distal femur condyle and tibia shaft. LAT precision differed between legs (p < 0.05) at the femur metaphysis, shaft, and tibia shaft. In the non-TKA leg, lateral positioning precision was numerically poorer at all ROIs; a generally similar pattern was observed in the TKA leg. The bone area post-TKA was small in the most distal femur and proximal tibia ROIs due to implant artifact. Tibial PA shaft reproducibility was confounded by fibular overlap in 23% of non-TKA scans but none post-TKA. However, fibula overlap was present on LAT view in 30% and 43% of non-TKA and TKA legs respectively.

Implications

Distal femur and proximal tibia BMD measurement may have utility for surgical planning and is best assessed in the PA projection. Based on precision, monitoring is best at the PA femur shaft and postoperatively at the tibial shaft. It is reasonable to expect precision improvement with automated ROI placement.

Purpose/Aims

The purpose of this study was to investigate the correlation between aromatase inhibitor-associated musculoskeletal symptoms (AIMSS) and ERα gene rs9340799,rs2234693 single nucleotide polymorphisms (SNPs) in breast cancer.

Rationale/Background

Aromatase inhibitor (AI) has a better effect on adjuvant therapy of hormone receptor-positive (HR+) breast cancers. AIs inhibit aromatase activity, reduce estrogen concentration, and improve survival rates for HR+ breast cancer patients. Despite the potential benefits, up to 50% of patients stop using AIs early. This is because AI can interfere with bone turnover, increasing the incidence of AIMSS. It has been confirmed that the risk of abnormal bone metabolism in healthy women is related to single nucleotide polymorphism (SNP) at two sites (rs9340799 and rs2234693) in the first intron of estrogen receptor alpha (ERα), but there have been few studies related to the risk of AIMSS. Our primary hypothesis was that ERα rs9340799 and rs2234693 would be associated with AIMSS.

Methods

From June 2015 to February 2022, 251 postmenopausal women with ER+ breast cancer who were receiving third-generation therapy were participated in this study. People with a medical history that included drug use or disease symptoms that were known to affect bone mineral metabolism were excluded. Each participant's peripheral blood was used to extract their entire genome, which was then amplified and sequenced for the chosen region. Dual energy X-ray absorptiometry was used to calculate the entire lumbar spine (spinal BMD) and the entire femur (femoral BMD).

Results

The BMD and T values of lumbar vertebrae in all ER α gene subtypes at rs9340799 were statistically significant (P=0.031,P<0.01), and the T value of lumbar vertebrae in A/A was higher than those in A/G and G/G (-0.957 ± 1.112 vs -1.313 ± 1.289 vs -1.76 ± 1.304). There were also significant differences in BMD and T values of lumbar vertebrae among rs2234693 genotypes (P=0.011, P < 0.01). The T values of T/T and C/T lumbar vertebrae were higher than those of C/C (-0.801 ± 1.085 vs -1.342 ± 1.067 vs -1.502 ± 1.591).

Although the femoral BMD trend of both SNPs is similar to that of lumbar vertebrae, there is no statistical difference.

Implications

Our findings suggest that C and G alleles may be susceptible genes for AMISS. These findings have potential clinical implications. In patients with C and G alleles, AMISS prevention is crucial, or tamoxifen may be appropriate for these patients to reduce risk.

Purpose/Aims

To investigate the precision and analysis protocol for VAT, SAT, and VAT/SAT ratio and explore precision covariates in a large prospective sample of children and young adults.

Rationale/Background

Visceral adipose tissue (VAT) has been linked to poor metabolic health, including obesity and metabolic syndrome. Excess VAT can have an early onset during childhood. VAT measured by DXA has been shown to well represent CT and MRI VAT in adults. However, few studies have shown repeatability and quality assurance issues for children.

Methods

These data have been collected as a part of a retrospective analysis of prospectively collected DXA scans acquired as part of two studies, the Bone Mineral Density in Childhood Study (BMDCS) and the Genome-wide Analysis Study (GWAS). The combined sample consisted of 2,514 children (10,787 scans, 1,271 girls) aged from 5 to 21 years. The whole-body DXA scans were acquired on five Hologic systems (Hologic, Inc., Marlborough, MA) of similar models (A and W) with up to eight years of annual follow-up between 2002 and 2009. All scans were analyzed centrally by the authors using one technologist using APEX 3.4 software. A unique and comprehensive quality assurance check was completed for all scans including a review of the acquisition criteria set by ISCD and a review of the automatically placed VAT regions of interest. During processing, regions were either repositioned or eliminated on DXA imaging. Duplicate scans were available on up to 150 children (71 girls) for precision assessment which was used to evaluate test-retest precision, both overall and by age group. Short-term precision estimates were calculated as the root mean square error and percent coefficients of variation (RMSE %CV). VAT codes were broken up into either invalidated scans or incorrectly positioned and subsequently corrected.

Results

Precision for all children in terms of %CV and RMSE (g) was 7.9% (12.8g) and 4.1% (24.7g) for VAT and SAT respectively. See Table 1. In general, the late teen group had the lowest precision error CV% (3.1-9.0) when compared to all other groups, and preteens had the highest %CV range (4.6-11.4). A pair of scans is shown in Figure 1 where the auto analyzer correctly positioned the regions of interest for the first scan but not for the second scan. Seven percent (752 scans) of the total number of scans had to be manually adjusted.

Implications

We conclude that the precision of the VAT regions is dependent on age where the precision for late teens is similar to that of adults. All Hologic DXA whole body scans in children should be manually reviewed for region placement for the most accurate and precise results.

Purpose/Aims

The aim of this study was to evaluate a new deep-learning artificial intelligence (AI) -based model for automated SpS. First, we compared bone mineral density (BMD), trabecular bone score (TBS) and bone surface area outcomes across three methods for SpS: 1) the manufacturer default, 2) the clinical DXA expert (criterion) and 3) the new AI-application. Second, we examined longitudinal reproducibility for the measurement of spine surface area.

Rationale/Background

The antero-posterior (AP) lumbar spine dual energy X-ray absorptiometry (DXA) scan is an important diagnostic measure, used for the assessment of osteoporosis. The quality of the scan is dependent on the accuracy of the vertebral bone mask, derived from bone edge detection and spine segmentation (SpS).

Reducing technical error requires manual validation of the default bone mask for each scan. However, this can be time-consuming in practice.

Methods

A sub-sample of 130 women (mean age: 67.1; BMI: 25.2; with no vertebral anomalies) were selected from the OsteoLaus population cohort, having previously received two LS DXA scans (GE Lunar iDXA, encore v 18), 2.5 years apart. Scans were analyzed according to each of the three methods (default, clinical expert and AI), and the primary outcomes (BMD, TBS and surface area) were compared using Student's t-tests and one-way repeated measures-ANOVA. The coefficient of variation (CV%) for bone surface area was also computed.

Results

There were significant differences in mean BMD and TBS outcomes derived from the default bone mask method compared to the DXA clinical expert (p=0.01, Table 1). There were no differences in BMD and TBS derived using the AI SpS bone mask method compared to the DXA clinical expert (p=0.67, Table 1).

Reproducibility for bone surface area was superior for the clinical expert and the AI model compared to the default method (Table 2).

Implications

The AI based model demonstrated improved accuracy and reproducibility for lumbar spine bone segmentation compared to the default analysis method, and in close agreement with the clinical criterion. Overall, these results suggest that the new AI-based model for automated SpS may be a valuable tool for reducing time and improving accuracy for the analysis of lumbar spine DXA scans.

Purpose/Aims

To evaluate the effects of 6 and 18 mo of abaloparatide (ABL) compared with placebo (PBO) on bone mineral density (BMD) in the acetabular regions of postmenopausal women with osteoporosis (OP).

Rationale/Background

Acetabular bone loss, as may occur in OP, increases risk of acetabular fragility fractures and is associated with significant morbidity. In total hip arthroplasty (THA), low acetabular BMD adversely affects primary stability, osseointegration, and migration of acetabular cups. ABL is an osteoanabolic agent for the treatment of men and postmenopausal women with OP at high risk for fracture that increases BMD of the total hip, femoral neck, trochanter, and lumbar spine. Effects of ABL on acetabular BMD are unknown.

Methods

Hip DXA scans were obtained at baseline, 6, and 18 mo from a random subgroup of postmenopausal women (aged 49–86 y) from the phase 3 ACTIVE trial randomized to either ABL 80 µg/d or PBO (n=250/group).

Anatomical landmarks were identified in each DXA scan to virtually place a hemispherical shell model of an acetabular cup and define regions of interest corresponding to DeLee & Charnley zones 1 (R1), 2 (R2), and 3 (R3). BMD changes compared to baseline were calculated for each zone. Statistical P values were based on a mixed-effect repeated measure model adjusted for BMI, age, and baseline BMD, with covariates including DXA scanner type, treatment group, visit, and treatment/visit interaction. DXA scans were aligned via intensity-based registration onto a reference scan to depict local mean changes in BMD.

Results

BMD in all zones were similar at baseline in the ABL and PBO groups. BMD significantly increased in the ABL group at 6 and 18 mo compared with PBO (all P< 0.0001 vs PBO; Figure), with mean BMD increasing from baseline by 8.38% in R1, 7.25% in R2, and 9.73% in R3 at 18 months. BMD in the PBO group was relatively stable over time.

Implications

Treatment with ABL resulted in rapid and progressive increases in BMD of all 3 acetabular zones. Increasing acetabular BMD has the potential to improve acetabular strength, which may reduce risk of acetabular fragility fractures. With bone health optimization prior to THA, increased acetabular BMD via ABL may provide better primary stability and longevity of acetabular cups in postmenopausal women with OP.