Fibrous Ring Lesions in Metacarpal Heads

I'd been seeing these rounded lucencies with well-defined, thin, sclerosed borders in metacarpal heads for a while, and almost called one an erosion in a patient. Turns out Keats (eighth edition, Fig 6-321) calls these ring lesions, probably fibrous and apparently of no clinical significance. I have not found peer-reviewed confirmation of this, however.