ESTIMATION OF CARTILAGE ESTIMATION OF CARTILAGE THICKNESS FROM JOINT THICKNESS FROM JOINT SURFACE SCANS:SURFACE SCANS:COMPARATIVE ANALYSIS OF COMPARATIVE ANALYSIS OF COMPUTATIONAL METHODSCOMPUTATIONAL METHODS

Author :Frank Heuer, Mark Sommers, John B. Reid III, Michael BottlangSource :BED-Vol. 50, 2001 Bioengineering Conference

ASME 2001Speaker : Ren-LI ShenAdvisor : Ku-Yaw Chang

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OutlineOutlineIntroductionMaterials and methodsResultDiscussion

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IntroductionIntroductionCartilage thickness and volume

◦characterize normal joints◦delineate joint degenerative disease

Compute cartilage thickness and volume from high-resolution joint geometry scans◦three distinct algorithms

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OutlineOutlineIntroductionMaterials and methodsResultDiscussion

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Materials and methodsMaterials and methodsJoint of a human cadaveric talus

◦obtained a laser displacement sensor◦scanning of a 31-mm x 34-mm

region of interest◦over 40,000 digitized surface points

Talar joint surface ◦intact articular cartilage (Atc)◦subchondral bone surface (Atb)

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Materials and methodsMaterials and methods

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Materials and methodsMaterials and methodsUse PV-Wave to compute cartilage

thickness from Atc and Atb in three distinct approaches◦a) vertical distance◦b) proximity method◦c) normal distance

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Materials and methodsMaterials and methodsIn addition to quantifying variances

◦closest approximation of the true cartilage thickness utilized a cylindrical object with two specific

radii 25.52-mm on one side 27.46-mm on the other

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Materials and methodsMaterials and methods

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Materials and methodsMaterials and methodsDefined thickness T=1.94-mm

◦idealized constant cartilage thickness distribution

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OutlineOutlineIntroductionMaterials and methodsResultDiscussion

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ResultResult

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Cartilage thickness variances◦depicted as a grey-scale image

ResultResult

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ResultResult

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OutlineOutlineIntroductionMaterials and methodsResultDiscussion

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DiscussionDiscussionThe other two methods

◦based on magnetic resonance imaging

◦based on stereophotogrammetry

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EndEnd

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