Asma Bint-Zubair¹, Gareth Jones^2,1, Mark Hopkinson¹, Andrew Pitsillides¹, Richard Meeson¹

¹The Royal Veterinary College, London, United Kingdom. ²University of Bristol, Bristol, United Kingdom

Objectives

To determine whether subchondral bone cysts are a feature of femoral head osteoarthritis in dogs and to assess their relationship with osteoarthritis severity.

Methods

A retrospective cross-sectional study was performed in which micro-computed tomography images of 28 normal and 36 osteoarthritic canine femoral heads were examined for subchondral bone cysts. Their presence, number, maximum diameter, and distance from the articular cartilage surface was recorded.

Results

Subchondral bone cysts were absent in femoral heads from dogs with no reported history or macroscopic evidence of osteoarthritis. Fifty percent (18/36) of diseased femoral heads contained at least one subchondral bone cyst. The size of subchondral bone cysts was associated with severity of cartilage disease (p = 0.0236) and 93% (n=41) were located peripherally.

Statement: Impact/ Clinical Significance

Subchondral bone cysts are a dynamic pathognomonic feature of canine femoral head osteoarthritis, with size reflecting cartilage disease severity. Therefore, subchondral bone cysts are potential imaging and predictive biomarkers for assessing canine osteoarthritis. By continuing efforts to further explicate and characterise their formation and features, we can strategically advance early diagnostics and develop targeted interventions that ultimately enhance treatment efficacy and quality of life for osteoarthritic patients.