Reproducibility of a peripheral quantitative computed tomography scan protocol to measure the material properties of the second metatarsal
1 School of Exercise Science, Australian Catholic University, Strathfield, NSW, Australia
2 Clermont Université, Laboratoire des Adaptations Métaboliques à l'Exercice en Conditions Physiologiques et Pathologiques, Clermont-Ferrand, France
3 Podiatry Department, Concord Hospital, South Western Sydney Local Health District, Sydney, NSW, Australia
4 Institute for Applied Health Research, Glasgow Caledonian University, Glasgow G4 0BA, UK
5 School of Medicine, University of Western Sydney, Penrith, NSW, Australia
6 The University of Sydney Discipline of Paediatrics and Child Health, Sydney, NSW, Australia
7 The University of New South Wales School of Women and Children’s Health, Sydney, NSW, Australia
8 The Sydney Children’s Hospitals Network Randwick and Westmead Department of Rheumatology, Sydney, NSW, Australia
9 The University of Sydney and Sydney Children’s Hospitals Network (Randwick and Westmead), Sydney, NSW, Australia
10 Department of Podiatry, Health and Rehabilitation Research Institute, School of Rehabilitation & Occupational Studies, AUT, Auckland, New Zealand
11 Bone Diagnostic Inc, Fort Atkinson, WI, USA
12 School of Science & Health, University of Western Sydney, Penrith, NSW, Australia
BMC Musculoskeletal Disorders 2014, 15:242 doi:10.1186/1471-2474-15-242Published: 19 July 2014
Peripheral quantitative computed tomography (pQCT) is an established technology that allows for the measurement of the material properties of bone. Alterations to bone architecture are associated with an increased risk of fracture. Further pQCT research is necessary to identify regions of interest that are prone to fracture risk in people with chronic diseases. The second metatarsal is a common site for the development of insufficiency fractures, and as such the aim of this study was to assess the reproducibility of a novel scanning protocol of the second metatarsal using pQCT.
Eleven embalmed cadaveric leg specimens were scanned six times; three times with and without repositioning. Each foot was positioned on a custom-designed acrylic foot plate to permit unimpeded scans of the region of interest. Sixty-six scans were obtained at 15% (distal) and 50% (mid shaft) of the second metatarsal. Voxel size and scan speed were reduced to 0.40 mm and 25 mm.sec-1. The reference line was positioned at the most distal portion of the 2nd metatarsal. Repeated measurements of six key variables related to bone properties were subject to reproducibility testing. Data were log transformed and reproducibility of scans were assessed using intraclass correlation coefficients (ICC) and coefficients of variation (CV%).
Reproducibility of the measurements without repositioning were estimated as: trabecular area (ICC 0.95; CV% 2.4), trabecular density (ICC 0.98; CV% 3.0), Strength Strain Index (SSI) - distal (ICC 0.99; CV% 5.6), cortical area (ICC 1.0; CV% 1.5), cortical density (ICC 0.99; CV% 0.1), SSI – mid shaft (ICC 1.0; CV% 2.4). Reproducibility of the measurements after repositioning were estimated as: trabecular area (ICC 0.96; CV% 2.4), trabecular density (ICC 0.98; CV% 2.8), SSI - distal (ICC 1.0; CV% 3.5), cortical area (ICC 0.99; CV%2.4), cortical density (ICC 0.98; CV% 0.8), SSI – mid shaft (ICC 0.99; CV% 3.2).
The scanning protocol generated excellent reproducibility for key bone properties measured at the distal and mid-shaft regions of the 2nd metatarsal. This protocol extends the capabilities of pQCT to evaluate bone quality in people who may be at an increased risk of metatarsal insufficiency fractures.