Background:Bone fragility is frequent in patients awaiting orthotopic liver transplantation (OLT) for severe liver disease, leading to a high prevalence of fractures, particularly vertebral ones. During the year following OLT, there is an early decrease in bone density and a high incidence of new vertebral fractures (VF).Objectives:To determine the prevalence of VF due to bone fragility during the year after OLT in a large population of patients.Methods:We conducted a cohort, prospective, descriptive, monocentric study including all the patients with severe chronic liver disease and awaiting OLT. Patients were seen during the pre-transplant period and one year after OLT. At each visit demographic, clinical, biological (including bone remodeling markers) and bone mineral density (BMD) data with VFA (Vertebral fracture Assessment) were collected. We estimated the incidence of VF after OLT. We compared biological and morphological data.Results:We have seen 272 patients before OLT (median age 59 years [Interquartile Range IQR: 53; 64], 75% male). Hepatopathy was due to alcoholic disease for 187 patients (69%). Before OLT, 12% had T-score<-2.5 SD (Standard Deviation) at lumbar spine site, 10% at total hip site and 10% at femoral neck site. Among the 272 patients, 31 had at least one VF (for a total of 49 VF). After OLT, we have seen 101 patients (median of 14 months [IQR: 5; 40] after OLT). For those 101 patients seen before and after OLT: we noted 18 VF for 12 patients (11.8%) before OLT and 29 VF for 18 patients (17.8%) after OLT on VFA. The VF incidence was 8.8 for 100 patients-years. During the year following OLT, there was a significant decrease of T-score at femoral neck and total hip sites. The number of osteoporotic patients was 13/101 (12.8%) at femoral neck and 14/101 (13.8%) at total hip. There was no significant change at the lumbar spine. Bone remodeling markers were significantly higher after OLT than before: CTX (μg/L) from 0.350 [IQR: 0.260; 0.501] before OLT to 0.490 [IQR: 0.279; 0.762] after OLT and osteocalcin (mg/mL) from 17 [IQR: 12; 22] to 30 [IQR: 19; 43], p<0.001. Fifteen of those 101 patients had an anti-osteoporotic drug prescribed before OLT despite being justified for 30 patients.Conclusion:Despite bone fragility and a high fracture risk, patients undergoing OLT are not enough treated for osteoporotic disease. It seems justified to offer a systematic rheumatology visit to detect bone damage before OLT and 6 months after OLT when the damage is the most significant. The drug prescription should be systematically proposed in a situation of fracture before OLT and/or in case of low bone parameters after OLT.References:[1]Krol CG, et al. Longitudinal Changes in BMD and Fracture Risk in Orthotopic Liver Transplant Recipients Not Using Bone-Modifying Treatment. J Bone Miner Res 2014;29(8):1763‑9.[2]Butin S, et al. High incidence of vertebral osteoporotic fracture within the first year after liver transplantation. Clin Exp Rheumatol 2017;35(6):913‑8.Acknowledgments:Elsa Cattelain-Lopez; Fabienne Chalier; Nelly Jaccaz-ValleeDisclosure of Interests:Chloe Plurien: None declared, Denis Mulleman Grant/research support from: Non-governmental organisation Lions Club Tours Val de France, French Society for Rheumatology., Consultant of: Pfizer, Novartis., Delphine Chu Miow Lin: None declared, Ephrem Salame: None declared, Philippe Goupille Grant/research support from: AbbVie, Amgen, Biogen, BMS, Celgene, Chugai, Janssen, Lilly, Medac, MSD, Nordic Pharma, Novartis, Pfizer, Sanofi and UCB, Consultant of: AbbVie, Amgen, Biogen, BMS, Celgene, Chugai, Janssen, Lilly, Medac, MSD, Nordic Pharma, Novartis, Pfizer, Sanofi and UCB, Speakers bureau: AbbVie, Amgen, Biogen, BMS, Celgene, Chugai, Janssen, Lilly, Medac, MSD, Nordic Pharma, Novartis, Pfizer, Sanofi and UCB, Isabelle Griffoul: None declared