Assessment on A-P DXA results of lumbar spine

AIM To analyze the effect of lumbar spinal degeneration on examination of bone mineral density (BMD). METHODS ① Fifty subjects aged from 45 to 65 were divided into three groups (normal, osteoporosis, osteopenia). They were respectively studied for the existence of lumbar spinal degeneration and low BMD by observing the value of BMD, the score of Nathan's. ② Cancellous bones were pre pared for the examination of electrical microscopy in osteoporosis cases with high Nathan score and normal axial BMD. RESULTS ① An inverse correlation was described between peripheral BMD and the score of Nathan's,while axial BMD and the score of Nathan's had positive correlation . ② When Nathan's score was 9, spinal degeneration increased the axial BMD significantly. ③ Under SEM, the spongy structures were destroied, lots of Howship's lacunaes formed and trabeculae became thin, perforated and absorbed in osteoporosis cases. CONCLUSION Although with the degeneration of vertebra the value of BMD doesn't decrease significantly, the structures of spongy bone has been destroyed. For early diagnosis and treatment of osteoporosis, we must asses the results of axial BMD with other image examination.