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Several small genetic association studies have been conducted for atypical femur fracture (AFF) without replication of results. We assessed previously implicated and novel genes associated with AFFs in a larger set of unrelated AFF cases using whole exome sequencing (WES). We performed gene-based association analysis on 139 European AFF cases and 196 controls matched for bisphosphonate use. We tested all rare, protein-altering variants using both candidate gene and hypothesis-free approaches. In the latter, genes suggestively associated with AFFs (uncorrected p-values <.01) were investigated in a Swedish whole-genome sequencing replication study and assessed in 46 non-European cases. In the candidate gene analysis, PLOD2 showed a suggestive signal. The hypothesis-free approach revealed 10 tentative associations, with XRN2, SORD, and PLOD2 being the most likely candidates for AFF. XRN2 and PLOD2 showed consistent direction of effect estimates in the replication analysis, albeit not statistically significant. Three SNPs associated with SORD expression according to the GTEx portal were in linkage disequilibrium (R2 ≥ 0.2) with an SNP previously reported in a genome-wide association study of AFF. The prevalence of carriers of variants for both PLOD2 and SORD was higher in Asian versus European cases. While we did not identify genes enriched for damaging variants, we found suggestive evidence of a role for XRN2, PLOD2, and SORD, which requires further investigation. Our findings indicate that genetic factors responsible for AFFs are not widely shared among AFF cases. The study provides a stepping-stone for future larger genetic studies of AFF., (© The Author(s) 2024. Published by Oxford University Press on behalf of the American Society for Bone and Mineral Research.)

Advancing age is accompanied by a reduction in bone formation and remodeling imbalance, which produces microstructural deterioration. This may be partly caused by a diversion of mesenchymal cells towards adipocytes rather than osteoblast lineage cells. We hypothesized that microstructural deterioration would be associated with an increased marrow adiposity, and each of these traits would be independently associated with nonvertebral fractures and improve discrimination of women with fractures from controls over that achieved by femoral neck (FN) areal bone mineral density (aBMD) alone. The marrow adiposity and bone microstructure were quantified from HR-pQCT images of the distal tibia and distal radius in 77 women aged 40 to 70 years with a recent nonvertebral fracture and 226 controls in Melbourne, Australia. Marrow fat measurement from HR-pQCT images was validated using direct histologic measurement as the gold standard, at the distal radius of 15 sheep, with an agreement (R 2 = 0.86, p < 0.0001). Each SD higher distal tibia marrow adiposity was associated with 0.33 SD higher cortical porosity, and 0.60 SD fewer, 0.24 SD thinner, and 0.72 SD more-separated trabeculae (all p < 0.05). Adjusted for age and FN aBMD, odds ratios (ORs) (95% CI) for fracture per SD higher marrow adiposity and cortical porosity were OR, 3.39 (95% CI, 2.14 to 5.38) and OR, 1.79 (95% CI, 1.14 to 2.80), respectively. Discrimination of women with fracture from controls improved when cortical porosity was added to FN aBMD and age (area under the receiver-operating characteristic curve [AUC] 0.778 versus 0.751, p = 0.006) or marrow adiposity was added to FN aBMD and age (AUC 0.825 versus 0.751, p = 0.002). The model including FN aBMD, age, cortical porosity, trabecular thickness, and marrow adiposity had an AUC = 0.888. Results were similar for the distal radius. Whether marrow adiposity and cortical porosity indices improve the identification of women at risk for fractures requires validation in prospective studies. © 2019 American Society for Bone and Mineral Research., (© 2019 American Society for Bone and Mineral Research.)

Osteoporosis and osteopenia are increasingly prevalent conditions among older adults. Not only do the fractures associated with poor bone health have significant health consequences for the individual, but also their economic impact is placing increasing financial burden on governments and society. This study aimed to determine the direct economic cost of osteoporosis, osteopenia, and fractures among Australians aged 50 years and older in 2017. This study uses previous Australian data on the incidence and prevalence of osteoporosis and osteopenia together with recent Australian data on health service utilization after fracture to provide an estimate of the economic burden of osteoporosis. A bottom-up costing approach was used to determine the average direct health care and non-health care total costs of a fracture, as well as the average community health service costs of managing individuals with osteoporosis or osteopenia. The total direct cost of osteoporosis in Australia in 2017 was estimated to be $3.44 billion (AUD 2017, USD 2.77 billion). Treatment of fractures accounted for 68% of total direct costs, and non-fracture management of osteoporosis accounted for 32%. Hip fractures accounted for the highest proportion (43%) of the total direct cost of fractures, although fractures at "other" sites accounted for 38.5%. Fractures among individuals aged 70 years and older accounted for 74% of the direct costs (55% and 19% in women and men, respectively). Fracture costs in those with osteopenia accounted for 50% of direct fracture treatment costs. This up-to-date cost analysis estimated that costs in 2017 were three times higher than in 2007. These estimates will aid clinicians, policy makers, researchers, and health care organizations to acknowledge the economic importance of reducing osteoporosis-related fractures and associated costs. This provides a strong public health case to promote bone health that will assist in reducing future fracture-related costs. © 2018 American Society for Bone and Mineral Research., (© 2018 American Society for Bone and Mineral Research.)