Response to injection of the navicular bursa with corticosteroid and hyaluronan following high-field magnetic resonance imaging in horses with signs of navicular syndrome: 101 cases (2000-2008).

The research paper aims to study the effect of injecting corticosteroid and hyaluronan into the navicular bursa, in horses diagnosed with navicular syndrome, and correlates the treatment success with specific MRI-detected abnormalities and the duration of lameness. The findings suggest that the disease process detected on MRI and the duration of lameness before treatment significantly influenced the treatment response.

Study Methodology

• Examining past records: The research conducted a retrospective case series study by reviewing the medical records of 101 horses diagnosed with navicular syndrome between January 2000 and December 2008.
• Data collection: Information such as horse usage, history, affected limbs, lameness duration, radiographic and MRI findings, treatments, and outcomes were collected for each horse. Follow-up information was acquired a minimum of 10 months post navicular bursa injection.

Findings

• Responses post treatment: Post the navicular bursa injection, 75% of the horses returned to their intended use for an average duration of 9.66 months, and 35% were sound at follow-up.
• Success based on lameness duration: Horses that were lame for less than 6 months before treatment were significantly more likely to return to their intended use, experience a longer positive response to treatment, and be sound at follow-up.
• Success based on MRI findings: Horses with primary deep digital flexor tendonitis responded most positively to the injection treatment with rest and rehabilitation. Those with navicular bursitis and horses with deep digital flexor tendonitis and adhesions to the collateral sesamoidean ligament of the distal sesamoid (navicular) bone responded moderately. However, horses with scar tissue in the proximal portion of the navicular bursa, adhesions from the navicular bone to the deep digital flexor tendon, or multiple abnormalities did not respond as well to treatment.

Conclusion

• The study concludes that the response to the injection treatment in horses with navicular syndrome is significantly dependent on the specific disease process revealed through MRI and the duration of lameness prior to treatment.