100,000 person-years respectively. The most significant predictors of osteoporotic fracture were history of fall (odds ratio 14.5) and fragility fracture (odds ratio 4.4). Other predictive factors included outdoor activity < 20 kg/cm 2 , difficulty bending forward, use of walking aid, and age ≥65 years. Each SD reduction in BMD at spine or hip was associated with 1.7 to 2.6-fold increase in fracture risk. Subjects with 5 or more clinical risk factors had an absolute 10-year risk of osteoporotic fracture of 6.2%, which increased to 18.2% if they also had total hip BMD T-score ≤-2.5. Addition of BMD information (total hip T-score score ≤-2.5) significantly enhanced fracture risk prediction when compared to clinical risk factors only (omnibus test p=0.001). Men with multiple risk factors and low BMD T-scores have a higher absolute fracture risk while men with no risk factors and normal BMD have a lower fracture risk than that predicted by FRAX. Conclusions: Clinical risk factors are population specific and the addition of BMD measurement to risk factor assessment improves fracture risk prediction in Southern Chinese men. doi:10.1016/j.bone.2010.09.104 OP16 Association of Cdx1 binding site of Periostin gene with bone mineral density and vertebral fracture risk Sumei Xiao 1 , Yi Gao 1 , Kam S. Lau 1 , Pak C. Sham 2 , Annie W.C. Kung 1 1 Department of Medicine, University of Hong Kong, Hong Kong, China 2 Department of Psychiatry, University of Hong Kong, Hong Kong, China Objective: The genetic determination of osteoporosis is complex and ill-defined. Periostin (POSTN), an extracellular matrix secreted by osteoblasts and a regulator of osteoblast differentiation and bone formation, may affect susceptibility to osteoporosis. The aim of this study was to investigate the association of POSTN gene with bone mineral density (BMD) and morphometric vertebral fractures. Meth- ods: The role of POSTN in the prediction of osteoporosis was investigated in a Chinese population including 1,572 subjects with extreme low or high BMD. We adopted a gene-wide association method followed by imputation-based verification and identification of causal variant(s). BMD was measured by dual X-ray absorptiometry at the lumbar spine and femoral neck. Morphometric vertebral fractures were identified by assessing vertebral height from X-rays of the thoracolumbar spine. Single marker and haplotype association analyses were performed with PLINK and imputation analyses with MACH. The putative transcription factor binding with target sequence was confirmed by electrophoretic mobility shift assay (EMSA). Results: Several SNPs in or around POSTN gene were associated with BMD variation or vertebral fracture risk. The most significant polymorphism was rs9547970, located - 2,327 bp upstream (p =0.00073, OR=1.41). It was further determined to be the variant that could best explain the association. A specific binding of Cdx1 to the wild-type site centering the rs9547970 major allele A of POSTN but not the variant G allele was confirmed by EMSA. Conclusions: Our results suggest POSTN as a novel candidate gene for osteoporosis, and further studies are required to confirm its influence on osteoporosis risk. doi:10.1016/j.bone.2010.09.105 OP17 Osteoclast lineage cells in conditional knockout of FGFR1 delayed fracture healing Xiumin Lu Third Military Medical University Daping Hospital, Chongqing, China Abstract content written in Chinese only. doi:10.1016/j.bone.2010.09.106 OP18 Predictive values of pQCT for non-vertebral fractures in elderly men Chyi Chyi Khoo 1 , Jean Woo 2 , P.C. Leung 3 , Anthony Kwok 4 , Kay Yuen 4 , Lin Qin 3 , Timothy Kwok 2 1 Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, China 2 Department of Medicine and Therapeutics, Prince of Wales Hospital, Chinese University of Hong Kong, Hong Kong, China 3 Department of Orthopaedics and Traumatology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China 4 CUHK Jockey Club Centre for Osteoporosis Care and Control, School of Public Health, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, China Objective: pQCT is shown to be able to discriminate those who had fracture and those who did not in Caucasian women, none prospective study was done in Asian elderly male population. We compared the capability of pQCT and DXA in prediction of non- vertebral fracture in Asian elderly men. Methods: One thousand seven hundred and twenty Chinese men aged 65–92 were measured for bone health status using pQCT and DXA and were followed-up for 4 years for fracture incidents. Fracture incidents were recorded and confirmed by X-rays or medical records. The associations of pQCT and DXA parameters with non-vertebral fracture were examined. Results: The average duration of follow-up was 4.6±1.4 years and 86 non- vertebral fractures were recorded. Among pQCT parameters, distal tibia trabecular BMD was most associated with non-vertebral fracture with an odd ratio (95% Confidence Interval (CI)) of 1.37(1.10–1.72) per SD reduction when adjusted with age. Hip BMD was associated non-vertebral fracture with odd ratio (95% CI) of 1.46(1.17–1.83) when adjusted with age. Area under the curve (AUC) (95% CI) of distal tibia trabecular BMD and hip BMD was 0.63(0.57–0.69) and 0.65(0.59–0.71), respectively. Although AUC of hip BMD was higher, it was not of statistical difference. Conclusion: Distal tibia trabecular BMD measured by pQCT could predict non-vertebral fracture in Chinese elderly men and its predictive value was comparable with DXA hip BMD. doi:10.1016/j.bone.2010.09.107 OP19 Comparative clinical study of the serum “iron overload indication” in elderly females with hi fracture induced by osteoporosis Youjia Xu Second Affiliated Hospital of Suzhou University, Suzhou, China Abstract content written in Chinese only. doi:10.1016/j.bone.2010.09.108 OP20 Enhanced attachment, proliferation and differentiation of bone marrow mesenchymal stem cells on a novel PLGA/TCP porous scaffold incorporating osteopromotive phytomolecule Icaritin Xinhui Xie 1 , Xinluan Wang 2 , Ge Zhang 2 , Xiaohong Wang 3 , Dong Yao 2 , Shihui Chen 2 , Ling Qin 24 1 The Chinese University of Hong Kong, Hong Kong SAR, China 2 Department of Orthopaedics And Traumatology, The Chinese University Abstracts / Bone 47 (2010) S361–S375 S367