Chemical arthrodesis of the distal tarsal joints using sodium monoiodoacetate in 104 horses.

This research evaluated the effectiveness of sodium monoiodoacetate in treating degenerative joint disease in horses‘ tarsometatarsal and distal intertarsal joints, through a process called chemical arthrodesis. The study showed promising results in improving the conditions of horses, with a comparable outcome to that of surgical procedures and minimal complications.

Research Methodology

• The researchers undertook a retrospective clinical study, identifying horses that had been diagnosed with degenerative joint disease in the tarsometatarsal and/or distal intertarsal joints. The diagnoses were based on the horses’ medical histories, their lameness examination results, radiographic findings, and for some, the response to intra-articular anesthesia or medication.
• The affected joints were treated with intra-articular injections of sodium monoiodoacetate, administered using 23 gauge needles while the horse was sedated but standing. The average dosage of sodium monoiodoacetate used was about 192 mg.
• To verify the accurate placement of the needles and assess potential communication with other synovial structures, a positive contrast arthrography of the distal intertarsal joint was performed on every horse.
• Post-treatment, horses followed a graded exercise program that began 7 to 10 days after the procedure.
• Follow-up lameness examinations and radiography, where possible, were conducted 3, 6, 12, and 24 months after the treatment.

Research Findings

• With time, more horses showed improvement. Specifically, 0 out of 57 horses were sound after 3 months, while this increased to 14 out of 55 horses after 6 months, 41 out of 50 horses after one year, and 29 out of 34 horses after two years.
• Based on radiographical evidence, ankylosis, or abnormal stiffness, of the treated joints was seen in a few horses at each checkpoint – 5 out of 55 after 3 months, 24 out of 38 after 6 months, 26 out of 30 after a year, and all 18 that remained after two years.
• Post-injection pain was reported in 6.7% of the horses, while significant complications that required further treatment occurred in 3.8% of them.

Conclusion

• The treatment of degenerative joint disease of the distal tarsal joints in horses using chemical arthrodesis with sodium monoiodoacetate was found to be effective.
• The results were comparable to those achieved through surgical arthrodesis, suggesting that this method could potentially be an alternative choice of treatment. Minimal equipment was needed and the procedure was done with the horse sedated and standing.
• As per this study, the risk of significant complications could be minimised with the correct injection volume and concentration and the adoption of a good technique.