Abstract
Objective The aim of this study was to evaluate the injection of a bone substitute material
(BSM) into an impact lesion in the palmar condyle of the third metacarpal bone.
Study Design This was an in vivo controlled study performed on six horses.
Materials and Methods Medial metacarpal condyles were exposed via arthrotomy and a compressive lesion created
in anaesthetized horses using 80 psi (27.6 MPa) onto the articular surface (n = 12). Paired limbs were randomly selected as a control or for extra-articular injection
of BSM towards the subchondral bone near the compressive lesion. Parameters of the
surgical techniques and BSM distribution outcomes were evaluated using magnetic resonance
imaging analysis, histology and histomorphometry.
Results Injection of the BSM required significant pressure, as well as the use of a pilot
hole. The BSM was visible in all magnetic resonance imagings in treatment limbs. Post-impact
treatment limbs had greater average grey scale values than controls (p = 0.041), and greater average grey scale values than pre-impact treatment limbs (p = 0.004). Histology demonstrated haemorrhage and microfractures at the site of compression
with no evidence of bone disruption from BSM injection.
Conclusion Injection of BSM into the dense subchondral bone of the equine palmar condyle could
be targeted to a site of injury, distributed subchondrally and without further injury
to bone or cartilage.
Clinical Significance This procedure has potential for the treatment of clinical impact injury or osteoarthritis
in horses, and long-term studies are warranted.
Keywords
subchondral bone - subchondroplasty - osteoarthritis - atheletes - impact injury
