Infrared thermography as a diagnostic tool to detect cranial cruciate ligament deficiency in dogs

Cranial cruciate ligament (CCL) disease is the leading cause of canine lameness. Diagnosis is based on physical examination and diagnostic imaging findings. Limitations of diagnostic modalities, including patient temperament, cost, availability, and need for general anesthesia, preclude their use for many patients. Infrared thermography is an easy, non-invasive diagnostic screening technique with use in both human and veterinary musculoskeletal conditions. The objective of this study was to investigate the utility of infrared thermography to diagnose CCL disease in a large population of client-owned dogs and investigate for correlations between ability of thermography to diagnose CCL deficiency and recorded explanatory factors. A commercial grade thermal imaging camera was used to collect preoperative images of both stifles in 50 dogs with surgically confirmed CCL rupture in one stifle and a normal opposite stifle. The average maximum temperatures of the affected and unaffected stifles were collected from these images and used for statistical analysis. Infrared thermography was not successful in differentiating between CCL-deficient and unaffected stifles in this cohort. No significant differences in average maximal temperature were observed between stifles when comparing to explanatory factors or variables. Use of infrared thermography should not be relied upon to diagnose canine CCL disease.