ArticleOsteoarthritis imaging2026
A novel method of determining bone mineral density of the knee from a pre-surgical CT scan to aid in surgical planning.
Article in Osteoarthritis imaging, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
0 citing papers in PubMed.
No citing paper in PubMed yet.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
4 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
introductionPatients with reduced bone mineral density (BMD) may have poorer outcomes after cementless joint replacement surgery. BMD phantoms may be used to calibrate Hounsfield units (HU) to BMD values, but BMD assessment with phantoms is not routine prior to surgery. We describe automated BMD calibration using air, fat and an aluminum motion-detection rod in Mako robotic-assisted knee arthroplasty 3D CT image volumes.
methodsUsing 6111 CT knee arthroplasty planning image volumes, including 133 with a BMD phantom (Mindways, TX), mean BMD values were determined for air, fat, and bone equivalent rods as calibration standards. Image voxels containing air were identified using histogram analysis. The rod surface was identified using an Active Appearance Model (AAM) search. At each point on the AAM-segmented femoral bone surface, lines perpendicular to the surface ("normal rays) were sampled and gaussian mixture model histogram analysis was used to identify fat. Ten iterations of 10-fold cross-validation were performed to compare calibration using either the phantom or the air, fat, and rod standards in tibial and femoral trabecular bone.
resultsTrabecular bone BMD from phantom calibrations were highly correlated with BMD values calculated using the air, fat, and rod standards for femur and tibia (r ≈ 0.98). Bland-Altman analysis showed negligible bias of ∼0.3 mg/cm3. The standard deviation of differences was 9.9. mg/cm3, suggesting an upper bound of precision of 9 mg/cm3 (precision error for Mindways phantom is 3.6 mg/cm3), which produces a coefficient of variation of 7.7% at mean BMD=117 mg/cm3.
conclusionAccurate volumetric BMD values may be derived at the knee from CT image volumes routinely acquired before robotic-assisted arthroplasty. This information may be useful in informing surgical decisions regarding the use of cementless implants, particularly in patients at risk of osteoporosis.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.