Bone marrow-derived mesenchymal stem cells (BMDMSCs) have been targeted for use in enhancement of bone healing; and their osteogenic potential may be further augmented by genes encoding bone morphogenetic proteins (BMP's). The purpose of this study was to compare the effect of genetic modification of human and equine BMDMSCs with BMP-2 or -7 or BMP-2 and -7 on their osteoblastogenic differentiation in the presence or absence of dexamethasone. The BMDMSCs were harvested from the iliac crest of three human donors and tuber coxae of three equine donors. Monolayer cells were genetically modified using adenovirus vectors encoding BMP-2, -7 or both and cultured in the presence or absence of dexamethasone. Expression of BMPs was confirmed by enzyme linked immunosorbent assay (ELISA). To evaluate osteoblastic differentiation, cellular morphology was assessed every other day and expression and secretion of alkaline phosphatase (ALP), as well as expression levels of osteonectin (OSTN), osteocalcin (OCN), and runt-related transcription factor-2 (Runx2) were measured for up to 14 days. Human and equine BMDMSCs showed a capacity for osteogenic differentiation regardless of genetic modification or dexamethasone supplementation. Dexamethasone supplementation was more important for osteoblastogenic differentiation of equine BMDMSCs than human BMDMSCs. Genetic modification of BMDMSCs increased ALP secretion with AdBMP-2 homodimer having the greatest effect in both human and equine cells compared to AdBMP 7 or AdBMP 2/7. BMP protein elution rates reached their maximal concentration between day 4 and 8 and remained relatively stable thereafter, suggesting that genetically modified BMDMSCs could be useful for cell-based delivery of BMPs to a site of bone formation. ß

Adequate fetlock stability can be achieved with an LCP, and although the repair is likely more stable it is approximately 3 times more expensive than using a limited contact dynamic compression plate (LC-DCP) with cortical screws.

Excellent stability of the carpal joints can be achieved with 2 LCP.

In March 2020, a symposium was held in Newmarket, UK, aiming to discuss measures which could be used internationally to reduce the risk of catastrophic fracture associated with the fetlock joint. The meeting was supported by the Gerald Leigh Charitable Trust, the Beaufort Cottage Charitable Trust and the Jockey Club with additional contributions from a number of industry stakeholders (Data S2). On the first day a panel of international experts (Data S1: The FRAT Group) discussed risk assessment protocols, particularly those based on imaging features which might indicate increased risk of imminent fracture. This was followed by a wider discussion with a diverse invited audience (Data S3), on how our current knowledge of fracture pathophysiology and risk factors for injury could be used to target risk assessment protocols. A delegates' survey on the key discussion points allowed quantification of opinions. This editorial highlights key meeting outcomes and identifies actionable items that can be taken forward with immediate effect. AUTH O R CO NTR I B UTI O N S All authors gave their final approval of the manuscript.

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