| dc.description.abstract | Clinically available scanning techniques are a potential detection tool for high density mineralised protrusions (HDMP) in human knees joints. Neil Thomas1, Nathan Jeffery1, Briony Dillon1, Valerie Adams1, Lakshminarayan Ranganath1, Rob van ‘t Hof1, Alan Boyde2, James Gallagher1 1University of Liverpool, Liverpool, UK 2Queen Mary University of London, London E1 4NS, UK High density mineralised protrusions (HDMPs) from the mineralising front into Hyaline articular cartilage (HAC), originally discovered in horses have been confirmed in human hip joints. Thought to be naturally occurring, these phenomena possess mineral concentrations greater than any healthy joint structure and have the potential to fragment. Thus, their presence would likely influence the biomechanical performance of surrounding tissues and they have been associated with osteoarthritis (OA). Incidence, location and morphology of HDMPs in human knees were assessed by two methodologies: In-vivo: MRI data of patients with Alkaptonuria (n=36; age=19–67) were acquired sagitally (in-plane resolution=0.58mm) and potential protrusions were assigned a confidence value (1–5; 1=least confidence), representing potential for misinterpretation. Ex-vivo: Knees (n=11) from 8 cadavers (age=74–97) were imaged isotropically (resolution=0.26mm) by dual echo steady state MRI. Size and location of potential protrusions were recorded. Knees were assessed for OA using the Kellgren-Lawrence (KL) scale. All knees had signs of OA (KL score ≥1). A total of 216 potential HDMPs were identified across both studies (in-vivo=180; ex-vivo=36), with ≥1 reported in 10 out of 11 cadaveric subjects and in all patients. Ninety-two percent of those noted in-vivo had a confidence score ≥3, indicating a low likelihood of misinterpretation. Distribution as variable, with potential protrusions noted in all areas of the joint. They were observed in isolation and in small clusters. The ratio of femoral to tibial protrusions in-vivo was 4.6:1 compared with 1.77:1, ex-vivo. The percentage of protrusions found in regions central to articulation was 50 in-vivo and 75 ex-vivo. The mean width and depth of protrusions within HAC were 1.67mm and 1.72mm. However, morphology varied considerably. Regions central to articulation typically experience the greatest stress within the knee. It is likely that the many HDMPs observed here would be subjected to fragmentation, at the detriment of surrounding HAC. This may account for clustering and is suggestive of a role in progression of arthropathy. Morphological variability may be indicative of different pathophysiological forms and stages. Crucially, these data suggest radiologic detection of HDMPs is possible with clinical technology. Moreover, it should be considered as a biomarker for predicting joint destruction. P040 page 117-118 Bone Research Society Annual Meeting 29 June- 1 July 2016 Liverpool DOI: 10.3389/978-2-88919-974-7 ISBN: 978-2-88919-974-7 Published in Frontiers in Endocrinology | en_US |
