Poster Presentation ESA-SRB-ANZBMS 2024 in conjunction with ENSA

Quantitative assessment of the tibiotalar joint using high-resolution peripheral quantitative computed tomography (HR-pQCT): a pilot study (#373)

Mícheál Ó Breasail 1 , Pholpat Durongbhan 2 , Vanessa Gan 1 , Daniel Yu 1 , Sheel Patel 1 , Peter R Ebeling 1 , Kathryn S Stok 2 , Ayse Zengin 1
  1. Department of Medicine, School of Clinical Sciences at Monash Health, Monash University, Clayton, VIC, Australia
  2. Department of Biomedical Engineering, The University of Melbourne, Parkville, Australia

Introduction:  Osteoarthritis at the ankle typically affects younger patients and can be caused by accidents or pathologies that lead to joint damage (e.g., haemophilic arthropathy (HA)). We piloted a tibiotalar joint imaging protocol using high-resolution peripheral quantitative computed tomography (HR-pQCT) in 66 participants using a 2-stack (168 slices each) method to assess joint space width (JSW) and volume (JSV).  However, many scans could not be reconstructed due to movement through the joint space which served as the boundary between stacks, and the medial gutter and medial malleolus were not captured in their entirety.  We explored whether a 3-stack protocol could mitigate these limitations to facilitate whole-joint imaging.

Methods: Ten healthy participants were scanned at the non-dominant ankle with HR-pQCT (XtremeCT II, SCANCO Medical AG, Switzerland) using two test protocols: 1) 2-stacks using with a reference line placed on the distal tibial endplate; 2) 3-stacks centred on the tibiotalar articulating surface.  Within both protocols, stacks were collected with interpolation of 20 slices (~12% overlap). Joint space width (JSW, mm) and volume (JSV, mm³) were calculated and presented as mean, standard deviation(SD).

Results:  The revised 3-stack protocol captured the tibiotalar joint in its entirety, including the medial gutter and medial malleolus (Figure 1). Overall JSW was similar between the 2-stack and 3-stack protocols, with mean(SD) of 2.57(0.57) and 2.62(0.56) respectively. The 3-stack protocol included the whole-joint and returned a greater JSV.

Conclusion: These preliminary data demonstrate the feasibility of whole-joint ankle imaging using HR-pQCT.  A revised 3-stack protocol was sufficient to image the entire joint in all participants. This protocol is currently being incorporated into a longitudinal study of haemophilia, where repeated joint bleeding often leads to painful and debilitating haemophilic arthropathy in load-bearing joints. Longitudinal HR-pQCT measured JSW and JSV may offer a useful marker of disease progression in HA.

 

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