The effect of bilateral palmar digital nerve analgesia on the compressive force experienced by the navicular bone in horses with navicular disease.

The research article talks about how pain management techniques can help lower stress on the navicular bone in horses suffering from navicular disease.

Objective of the Study

This study evaluates the impact of analgesia, specifically a bilateral palmar digital nerve block, on the force experienced by the navicular bone in horses with navicular disease. The compressive forces on the bone when the horse stands, as well as stride kinematics, were measured before and after applying the nerve block.

Methodology

• Seven horses with clinical, radiographic, and scintigraphic signs of navicular disease underwent forceplate and kinematic analysis.
• The analysis was carried out before and after desensitization of the heel area with a bilateral palmar digital nerve block.
• Both the compressive force exerted on the navicular bone during stance and stride kinematics were determined in each state.

Results and Findings

• The analgesia resulted in a decreased compressive force on the navicular bone during the standing time of the horse.
• The average peak force at the start of standing was 7.05±1.10 N/kg before and 6.46±1.15 N/kg after the nerve block (P = 0.01).
• At the end of the stance, these values were 5.00±2.05 N/kg before and 4.39±1.65 N/kg after the nerve block (P = 0.05).
• This suggested that horses respond to heel pain, including pain in the navicular region, by constricting the deep digital flexor muscle to remove the load from their heels.
• This reaction increases the compressive load on the navicular bone, leading to possible remodeling and possible damage to the overlying flexor cartilage.
• This cartilage damage can be painful and is identified as navicular disease.

Conclusion

The study suggests that navicular disease could be a possible end stage for various heel-related conditions in horses. By managing pain via techniques such as the bilateral palmar digital nerve block, the stress experienced by the navicular bone can be potentially reduced, which could potentially improve the condition of those suffering from navicular disease.