Precision of a photogrammetric method to perform 3D wound measurements compared to standard 2D photographic techniques in the horse




Reasons for performing study: Methods of 3D wound imaging in man play an important role in monitoring of healing and determination of the prognosis. Standard photographic assessments in equine wound management consist of 2D analyses, which provide little quantitative information on the wound bed.

Hypotheses: 3D imaging of equine wounds is feasible using principles of stereophotogrammetry. 3D measurements differ significantly and are more precise than results with standard 2D assessments.

Methods: Repeated specialised photographic imaging of 4 clinical wounds left to heal by second intention was performed. The intraoperator variability in measurements due to imaging and 3D processing was compared to that of a standard 2D technique using descriptive statistics and multivariate repeated measures ANOVA.

Results: Using a custom made imaging system, 3D analyses were successfully performed. Area and circumference measurements were significantly different between imaging modalities. The intraoperator variability of 3D measurements was up to 2.8 times less than that of 2D results. On average, the maximum discrepancy between repeated measurements was 5.8% of the mean for 3D and 17.3% of the mean for 2D assessments.

Conclusions: The intraoperator repeatability of 3D wound measurements based on principles of stereophotogrammetry is significantly increased compared to that of a standard 2D photographic technique indicating it may be a useful diagnostic and monitoring tool.

Potential relevance: The equine granulation bed plays an important role in equine wound healing. When compared to 2D analyses 3D monitoring of the equine wound bed allows superior quantitative characterisation, contributing to clinical and experimental investigations by offering potential new parameters.