Regional variations in cartilage thickness of the radial head; implications for prosthesis design

Abstract

BackgroundKnowledge of potential variations in cartilage thickness is important in designing radial head implants.ObjectiveTo characterize the regional variations in radial head cartilage thickness.MethodsTwenty‐seven cadaveric radii were dissected and scanned with computed tomography (CT) in neutral position. Three dimensional models were generated from CT scans and processed through a computer program by two independent observers. Cartilage thickness values were obtained at 41 predetermined landmarks located around the articular dish and side of the radial head.ResultsAt the side of the radial head, cartilage in the posteromedial quadrant (0° to 90°) was significantly thicker than all other quadrants (p < 0.05). Cartilage thickness measurements within the articular dish were similar at a mean of 0.98 ± 0.13mm, but increased towards the rim of the radial head (p < 0.001). Regional variations of cartilage thickness within the rim circumference were also detected, with the thickest region located anteriorly (270°, p < 0.001) and thinnest region laterally (180°, p < 0.05).ConclusionsRegional variations in cartilage thickness exist around the side of the radial head and within the articular dish. Such differences offer insight into the biomechanics of the elbow joint and may also affect overall radius length and dish depth, which may be clinically important for implant design.Funding:DepartmentalGrant Funding Source: Departmental