Study of Bone Mineral Density and Trabecular Bone Score in Patients With Ankylosing Spondylitis

"structural damage in the cervical and lumbar spine was scored according to the modified Stoke AS Spinal Score (mSASSS) which yielded a final summation score ranging from zero to 72.~BMD was measured using DXA (Lunar Prodigy densitometer, GE Healthcare, Madison, WI, USA).~BMD was measured at the lumbar spine (L1-L4) and the left hip (femoral neck and total proximal femur).~TBS was analyzed using DXA images over exactly the same region as the lumbar BMD assessment (L1-L4). Lumbar spine DXA images were reanalyzed using TBS iNight software version 2.1 (Med-I maps, Merignac, France). Patients were divided in 3 TBS groups according to guidelines for fracture risk \[22\]: any TBS \>1.31 was considered as normal; TBS values between 1.23 and 1.31 were consistent as partially degraded structure; and any TBS \<1.23 was considered as degraded structure."