Osteoarthritis, Tarsus - Equine
Polish Warmblood, M, 8 year-old
This patient had a history of a subtle lameness and decrease in athletic performance since being worked hard as a 2 year-old. He had been kept serviceably sound using intra-articular injections of corticosteroids (five injections over the previous 12 months with the last injection given 45 days before examination).
Physiological Screen with Digital Thermal Imaging
Thirty-two digital thermal images were captured with a Digatherm IR camera.
Thermal asymmetry with hyperthermia was noted over the entire distal metatarsus and tarsal-metatarsal joint and was most notable over the medial aspect of the joint (Fig. 1).
Fig. 1 – Anterior-posterior thermogram of the hind limbs. Zone 1 on the medial aspect of the left hock has a 2.2oC higher temperature than Zone 2 on the medial aspect of the right hock.
Analysis of the thermal gradients on each hind limb indicated a 2.2°C higher temperature over the medial left hock versus the corresponding area on the right hock (Fig. 2).
A tarsocrural joint block resulted in a 75% increase in soundness.
Multiple radiographs were taken of the left hock.
Fig. 2 – Thermograms of the medial aspect of the right and left hocks.
Pathological changes consistent with osteoarthritis and degenerative joint disease were noted throughout the left hock. Osteophyte formation was noted in multiple locations on multiple views (Fig 3).
Value of the Digital Thermal Images
This patient presented with a left hind limb lameness. Digital thermal imaging confirmed the need for a selective nerve block and radiographs and promoted client compliance with the diagnostic recommendations.
The patient was retired from competition to stand at stud.
The thermal images will serve as baseline data for continued monitoring of the patient.
Fig. 3 – Radiographs of the left hock.
Kelly Jewell PhD Thermography UK