Patients with diffuse idiopathic skeletal hyperostosis do not have increased peripheral bone mineral density and...

Area of Science:

• Orthopedics and Bone Metabolism
• Radiology and Imaging
• Rheumatology

Background:

• Diffuse idiopathic skeletal hyperostosis (DISH) is characterized by extraskeletal ossification.
• Previous dual-energy X-ray absorptiometry (DXA) studies suggested elevated areal bone mineral density (aBMD) in DISH patients.
• The accuracy of DXA in DISH may be confounded by ossification at tendon and ligament insertion sites.

Purpose of the Study:

• To investigate volumetric bone mineral density (vBMD) and bone geometry in DISH patients using peripheral quantitative computed tomography (pQCT).
• To compare appendicular skeletal parameters between individuals with DISH and healthy controls.
• To clarify discrepancies between DXA-based aBMD and actual bone characteristics in DISH.

Main Methods:

• Recruitment of 30 DISH patients and 30 age- and height-matched healthy controls.
• pQCT assessment of the radius, tibia, and third metacarpal bone at distal epiphyses and mid-shafts.
• Measurement of bone cross-sectional area (CSA), total BMD, trabecular BMD, cortical CSA, cortical wall thickness, and cortical BMD.

Main Results:

• No significant differences were observed in any measured bone parameters between the DISH group and the control group.
• This includes total bone CSA, cortical CSA, cortical thickness, and vBMD at both epiphyseal and diaphyseal sites.
• Muscle and fat CSA of the forearm and lower leg also did not differ between groups.

Conclusions:

• Contrary to DXA-based findings, pQCT demonstrates that DISH patients do not exhibit increased vBMD or altered bone geometry in the appendicular skeleton.
• The study suggests that DXA may overestimate aBMD in DISH due to extraskeletal ossification.
• These findings highlight the importance of advanced imaging techniques like pQCT for accurate bone assessment in DISH.