Comparing imaging modalities and healing criteria for the estimation of fracture age: a systematic review

The estimation of fracture age is important for both clinical and forensic purposes. The objective of this systematic review is to identify the imaging modalities currently used in clinical and forensic practice for fracture ageing, with a view to appraise technologies used, patient demographics studied in research, and the healing stages and criteria defined to estimate time since injury. After conducting a bibliographic literature search, we identified 21 suitable publications for inclusion in the review. Comparison of the literature for fracture ageing found that most research has used 2D radiography, predominantly using an antemortem paediatric population. The remaining publications used MRI, CT, histology, and macroscopy. Although the most frequent number of radiographic stages assessed was six, no two methods assessed the same combination of features. Indeed, variation in the number and definition of healing stages rendered comparison between the publications challenging. Consequently, limited work has been carried out to validate existing methods of ageing. The results therefore reiterate the need for caution in the use of radiographic modalities for forensic fracture ageing. Histology remains the undisputed gold standard, however it is a destructive and exclusively postmortem method. As such, there is need for further research to investigate the potential of additional imaging modalities such as micro-CT, with a high-resolution, 3D, and non-destructive nature. This can serve as a valuable complement to help support and navigate the challenges associated with traditional histopathological methods.