Povidone-iodine lavage treatment of experimentally induced equine infectious arthritis.

This research is about comparing the effectiveness of povidone-iodine solution with balanced electrolyte solution when used for lavage treatment of infectious arthritis caused by Staphylococcus aureus in horses.

Methodology

The study was carried out by inducing infectious arthritis in both tarsocrural joints of 4 horses by injecting them with 1.5 X 10(5) colony-forming units of Staphylococcus aureus.

• One tarsocrural joint of each horse was lavaged with balanced electrolyte solution, while the contralateral tarsocrural joint was lavaged with 0.1% povidone-iodine solution. This procedure was carried out on days 1, 3, and 6.
• As part of the treatment protocol, all horses were also orally administered trimethoprim (5 mg/kg)/sufadiazine (25 mg/kg) combination twice daily and phenylbutazone (2 g) once daily for the period of 21 days which was the study duration.
• Synovial fluid specimens were collected and examined on days 0, 1, 3, 6, 9, 14, and 21. These specimens were analyzed for color, clarity, total protein concentration, WBC count and differential, mucin clot-forming ability, and bacteriological culture on certain days.
• On the final day of the study (day 21), all horses were euthanatized and the tarsocrural joints were opened for examination. Synovial membrane specimens and articular cartilage specimens were also collected and evaluated bacteriologically, histologically, and histochemically.

Statistical Analysis

• The research used statistical analysis methods like repeated measures analysis of variance to evaluate differences between lavage solutions used and among days for objective measurements.
• A paired t test was applied to evaluate differences between solutions for the indices of synovial membrane inflammation and cartilage staining intensity.
• A result was considered statistically significant if the probability of a type-I error was less than 0.05.

Findings

The research found no significant differences between joints lavaged with the electrolyte solution or povidone-iodine solution when comparing synovial total protein concentration, WBC count, results of synovial fluid and membrane bacteriologic culture, synovial membrane inflammation, or articular cartilage glycosaminoglycan concentration. This indicates that both types of solution are comparably effective in treating infectious arthritis in the horses.