PMC

Relation between frequency (number, n) and of type of denuded areas of subchondral bone (dAB) within each cartilage plate.

Example images showing internal osteophytes without segmentation (arrows) in central lateral femur (cLF, top left), LT (bottom left), central medial femur (cMF, top right) and MT (bottom right).

Relation between the relative frequency (%) of knees affected by any denuded area of subchondral bone (dAB) and cKL grades for men and women, respectively. The frequency differed significantly across cKL grades.

Different phenotypes of denuded areas of subchondral bone (dAB): internal osteophyte (left) and full thickness cartilage loss (right). The top row shows the un-segmented MR image, the bottom row the segmented MR image.

Frequency of the number of discontinuous areas (1–4) of denuded subchondral bone (dAB) observed in each cartilage plate (N = 245); MT; cMF, weight-bearing medial femoral condyle; LT; cLF, weight-bearing lateral femoral condyle.

Relation between the relative frequency (%) of knees affected by denuded area of subchondral bone (dAB) exclusively representing internal osteophytes, or full thickness cartilage loss, or a combination of both type with cKL grades 1–4; cMF, weight-bearing medial femoral condyle; cLF, weight-bearing lateral femoral condyle.

Frequency distribution of the main location of discontinuous denuded areas of subchondral bone (dAB) in the femorotibial subregions. The values give the percentage of cases in which a given subregion displayed dAB >10% of the subregion size in the 245 cases affected by “any” subregion. The total number of plates affected by dABs was 94 (cMF), 89 (cLF), 90 (MT) and 116 (LT). Note that any one knee could have dAB affecting >10% in more than one subregion (or no subregion affected by dAB > 10%) in each cartilage plate. cMF, weight-bearing medial femoral condyle; cLF, weight-bearing lateral femoral condyle; MT; LT; e, external, c, central; i, internal; a, anterior; p, posterior.