Comparing CT to surface digitization‐based measurements of cartilage thickness

Abstract

BackgroundKnowledge of cartilage thickness distribution is important for understanding the biomechanical properties of different joints. In recent studies, various techniques for measuring cartilage thickness have been assessed.ObjectiveCompare the reliability of computed tomography (CT) and surface digitization‐based methods for measuring cartilage thickness.MethodsSix cadaveric radii were CT scanned in air, barium sulfate, and iopamidol to determine which medium enabled optimal cartilage visualization. Images of cartilage in the best medium were used to generate three dimensional (3D) models for measurement. The radial heads were then digitized using an infrared motion tracking system. Cartilage thickness was measured as the distance from the deepest point on the cartilage surface to the bone. Both CT‐ and surface digitization‐based values were compared to physical measurements acquired using a digital caliper to determine which technique was most reliable for assessing cartilage thickness.ResultsCT and surface digitization had mean differences of −0.01±0.06mm (mean ± standard deviation) and 0.00±0.35mm, respectively. Surface digitization‐based measurements, however, had larger individual errors and a greater range of error (−0.42 to +0.62mm) compared to CT‐based measurements (−0.07 to +0.08mm).ConclusionsCT is a more reliable technique for assessing cartilage thickness.Grant Funding Source: Departmental