Evaluation of a Novel Bone Substitute Injection Technique for Potential Treatment of Impact Injury to the Equine Palmar Metacarpal Condyle.

This research article focused on evaluating the effectiveness of injecting a bone substitute material (BSM) into an impact-induced lesion in the palmar condyle of the third metacarpal bone in horses. The researchers found that BSM could be precisely targeted at the site of injury and distributed throughout the affected area without causing additional damage to bone or cartilage. This new technique shows potential in treating impact injuries or osteoarthritis in horses, necessitating further long-term studies.

Methodology

• In the controlled study, six horses were used as subjects. The medial metacarpal condyle (a part of their lower leg bone) in the horses was revealed through arthrotomy (surgical incision into a joint).
• A compressive lesion or impact injury was artificially created on the anaesthetized horses using 80 psi (27.6 MPa) focused on the articular surface. This created a total of 12 such lesions.
• Paired limbs were then randomly selected for control or for the injection of BSM directed towards the subchondral bone near the compressive lesion.

Results and Measurements

• The study found that the injection of BSM required considerable pressure and the usage of a pilot hole to direct it accurately. Once injected, BSM was visible in all the magnetic resonance imaging (MRI) scans taken from the treatment limbs.
• Post-impact treatment limbs showed higher average grey scale values on MRI scans than controls, indicating the presence of BSM. Similarly, these post-impact limbs also had higher grey scale values than their pre-impact counterparts.
• Furthermore, histology (the study of the microscopic structure of tissues) showed that although haemorrhage and microfractures were present at the site of compression, there was no evidence of further bone disruption caused by the BSM injection.

Conclusions

• The research concluded that BSM injection into the dense subchondral bone of the equine palmar condyle could be precisely aimed at an injury site, spread subchondrally (underneath the cartilage surface), and done without causing further injury to the bone or cartilage. This indicated the potential efficacy of BSM in treating equine bone injuries.
• The researchers suggested that this procedure could be a viable treatment method for clinical impact injuries or even osteoarthritis in horses. However, they also underlined the need for more extensive long-term studies to further evaluate this potential treatment technique.