Large enthesophytes in teenage skulls: Mechanical, inflammatory and genetic considerations

The literature implies that large enthesophytes are exclusive to genetically predisposed individuals and to Spondyloarthropathies sufferers. Accordingly, the aim of this investigation and report was to assess the involvement of genetic predisposition, inflammatory and/or mechanical influences in the development of large enthesophytes in a sample population of teenagers presenting with large enthesophytes emanating from the external occipital protuberance.

Analysis was based on four teenage males (13-16 year-old) possessing 14.5-30.5 mm enthesophytes projecting from the external occipital protuberance. This study included assessment of radiographs, MRI scans, blood-work, history, the SF-36 health survey, and the comparison of these data with the relevant literature to describe the interrelationships between the presence of enlarged external occipital protuberance, forward head protraction, active inflammation and/or genetic factors.

Known genetic markers (e.g. HLA-B27) were not detected by allele-specific primers and both ESR and CRP tests were negative. Additionally, MRI analyses failed to detect active localised inflammation at the external occipital protuberance and surrounding structures. The health survey yielded normal parameters for all participants. All participants displayed significantly large Forward Head Protraction values (>40 mm), and interviews with participants and their parents indicated that concerns related to posture were prevalent since early childhood.

This report suggests that mechanical load has an important role in enthesophyte development, irrespective the involvement of inflammatory or genetic factors.