Are CT-Based Finite Element Model Predictions of Femoral Bone Strengthening Clinically Useful?

Abstract

Purpose of ReviewThis study reviews the available literature to compare the accuracy of areal bone mineral density derived from dual X-ray absorptiometry (DXA-aBMD) and of subject-specific finite element models derived from quantitative computed tomography (QCT-SSFE) in predicting bone strength measured experimentally on cadaver bones, as well as their clinical accuracy both in terms of discrimination and prediction. Based on this information, some basic cost-effectiveness calculations are performed to explore the use of QCT-SSFE instead of DXA-aBMD in (a) clinical studies with femoral strength as endpoint, (b) predictor of the risk of hip fracture in low bone mass patients.Recent FindingsRecent improvements involving the use of smooth-boundary meshes, better anatomical referencing for proximal-only scans, multiple side-fall directions, and refined boundary conditions increase the predictive accuracy of QCT-SSFE.SummaryIf these improvements are adopted, QCT-SSFE is always preferable over DXA-aBMD in clinical studies with femoral strength as the endpoint, while it is not yet cost-effective as a hip fracture risk predictor, although pathways that combine both QCT-SSFE and DXA-aBMD are promising.

Cost-Effectiveness of Osteoporosis Screening Using Biomechanical Computed Tomography for Patients With a Previous Abdominal CT

“…Such a low value of ICER—almost cost saving—is consistent with our findings because their program required extra payment for a dedicated CT scan whereas ours did not. Others have calculated that BCT could be cost‐effective in the United Kingdom—at a cost of £14,656/QALY — if offered at a fee of $100 to all patients who test positive for osteopenia by DXA, the BCT analysis also requiring payment for a dedicated CT exam . Again, our results are consistent with that low value of ICER, considering overall care costs are lower in the United Kingdom than the United States and our proposed (ancillary) BCT program does not require extra payment for a dedicated CT. We emphasize that these prior analyses assessed general use of BCT with DXA, which would increase radiation exposure and cost by requiring a dedicated CT exam for the BCT analysis.…”

“…For DXA, we did not vary the cost because it approximated the hospital‐based fee set by CMS . For BCT, pricing has not yet been established in the United States and thus we varied pricing up to $250, the latter being about 25% lower than a price reported in the United Kingdom …”

“…We sought to assess the clinical and economic benefits of such an ancillary BCT‐based, standing‐order screening program in women and men age 65 years and older. Two recent cost‐effectiveness analyses for women showed that BCT can be cost effective (versus usual care) when used for screening generally, by using both DXA and a dedicated hip CT scan ordered specifically for the BCT analysis . In those analyses, the overall cost of the BCT test would be the sum of the costs for acquiring the CT scan and then analyzing the scan with BCT analysis.…”

“…Two recent costeffectiveness analyses for women showed that BCT can be cost effective (versus usual care) when used for screening generally, by using both DXA and a dedicated hip CT scan ordered specifically for the BCT analysis. (25,26) In those analyses, the overall cost of the BCT test would be the sum of the costs for acquiring the CT scan and then analyzing the scan with BCT analysis. Those cost-effective analyses did not address an ancillary approach for patients already undergoing CT and did not address men.…”

The influence of anisotropic voxel caused by field of view setting on the accuracy of three-dimensional reconstruction of bone geometric models

“…4,[11][12][13][14] In addition to DXA and QCT, more researchers tend to use the finite element analysis (FEA) method to investigate bone features, 4,[15][16][17][18] since FEA reveals information of the three-dimensional (3D) morphology, the material property and the loading distribution of bone, which may provide a more accurate bone strength prediction. 4,16,17,[19][20][21][22][23] Among all factors that affect FEA analysis results, a critical one is bone geometric model. 22 Digital Imaging and Communications in Medicine (DICOM) is the international standard of medical imaging.…”