Fully automated segmentation of callus by micro-CT compared to biomechanics

Abstract

BackgroundA high percentage of closed femur fractures have slight comminution. Using micro-CT (μCT), multiple fragment segmentation is much more difficult than segmentation of unfractured or osteotomied bone. Manual or semi-automated segmentation has been performed to date. However, such segmentation is extremely laborious, time-consuming and error-prone. Our aim was to therefore apply a fully automated segmentation algorithm to determine μCT parameters and examine their association with biomechanics.MethodsThe femura of 64 rats taken after randomised inhibitory or neutral medication, in terms of the effect on fracture healing, and controls were closed fractured after a Kirschner wire was inserted. After 21 days, μCT and biomechanical parameters were determined by a fully automated method and correlated (Pearson’s correlation).ResultsThe fully automated segmentation algorithm automatically detected bone and simultaneously separated cortical bone from callus without requiring ROI selection for each single bony structure. We found an association of structural callus parameters obtained by μCT to the biomechanical properties. However, results were only explicable by additionally considering the callus location.ConclusionsA large number of slightly comminuted fractures in combination with therapies that influence the callus qualitatively and/or quantitatively considerably affects the association between μCT and biomechanics. In the future, contrast-enhanced μCT imaging of the callus cartilage might provide more information to improve the non-destructive and non-invasive prediction of callus mechanical properties. As studies evaluating such important drugs increase, fully automated segmentation appears to be clinically important.

Synthesis and Evaluation of Galloyl Conjugates of Flavanones as BMP-2 Upregulators with Promising Bone Anabolic and Fracture Healing Properties

“…Tb.N was significantly increased, while Tb.Th showed an increasing trend in 5e -treated rats compared with the vehicle (Figure C). Increased BV/TV, Tb.Th, and Tb.N at the fracture site indicated greater callus formation through new bone regeneration (woven bone), which would facilitate its transformation into the lamellar bone and improved callus biomechanical property . From the calcein labeling study, we observed that 5e (5 mg/kg) was comparable to PTH (130% increase with 5e vs 184% with PTH) (Figure D,E).…”

Characterization of the Developing Lacunocanalicular Network During Fracture Repair

“…For some quantitative analysis, manual segmentation was performed as automated segmentation of fractures can be particularly challenging. While there have been efforts to develop programs that enable accurate automated µCT segmentation (32) , to date they remain less accurate than manual approaches. µCT can increase in power when combined with other scanning and analysis modalities.…”

Image-based radiodensity profilometry measures early remodeling at the bone-callus interface in sheep

“…The process for segmentation of cortical bone and callus was based in part on previously reported methods (Buie et al 2007; Morgan E, Mason Z, Chien K, Pfeiffer A, Barnes G, Einhorn T et al 2009;Bissinger et al 2017). To complete this task, the algorithm required two initial estimates of the segmentation thresholds.…”