Introduction
Bone is critically involved in OA pathology with features such as sclerosis and osteophytes appearing early in disease development [1]. The imaging modalities of choice for OA assessment are radiography and magnetic resonance imaging. However, there are significant advantages to CT imaging compared to these modalities. Primarily, CT is capable of high-resolution three-dimensional image reconstruction allowing standardised bone structure analysis. Therefore, the objective of this systematic review was to gain an overview of published CT parameters for the assessment of subchondral bone in OA, and current practices and standards.
Methods
Search strategies were run in Medline, Embase, and Cochrane Library databases (2010-January 2023) and results were independently screened by two reviewers. Pre-determined inclusion/ exclusion criteria deemed studies conducted with CT in vivo/ex vivo in human adults (>18 years) to assess subchondral bone in OA eligible. Data was extracted from included studies and analysed in a qualitative summary and formal narrative synthesis.
Results
Of all search results, 202 studies were deemed eligible. The CT modalities used were summarised in four groups: micro-/nano-CT, conventional clinical-type CT, quantitative CT, and cone-beam CT (Fig. 1a). Nine anatomical locations were found to be of interest for OA assessment (Fig. 1b). Six parameter categories were identified that combine measurements of related osseous features: microstructure, bone adaptation, gross morphology, mineralisation, joint space, and mechanical properties (Fig. 1c).
Conclusions
CT techniques are increasingly popular for OA assessment and clinically meaningful CT measurements as well as parameters with the potential to perform in the clinical field. Quantification is crucial for their sensitivity and reproducibility. Finally, consistent reporting and standardised measurement protocols enhance the value of parameters in future OA research and clinical practice.
Figure 1 | Overview of a) use frequency of CT groups, b) investigation frequency of anatomical locations, and c) reporting frequency of parameter categories.