Synovial sepsis is rare following intrasynovial medication in equine ambulatory practice.

The research aims to quantify the risk of synovial sepsis, a serious infection, after injecting medication directly into a joint in horses. It was found that over the period of six years, only four horses out of almost 10,000 treatments developed this complication, indicating a very low risk.

Objective and Methods

• The objective of this study was to understand the occurrence and risk of synovial sepsis, a type of joint infection, following intrasynovial injections, which are injections directly into a joint, in horses. This type of study is fundamental in helping medical practitioners make informed decisions and gain consent from owners before undertaking procedures.
• For the research, medication records were examined and cross-checked against submissions for synovial cytology, a microscopic examination of cells within the synovial fluid in a horse’s joint, and hospital admissions specifically related to synovial sepsis.
• The focus was on interest areas including the age and sex of the horse, as well as the type of product used for medication.

Results

• Between 2006-2011, a total of 9456 intrasynovial medications were performed, split into 4331 sessions. The most commonly used medications were corticosteroids, hyaluronate, and amikacin sulphate.
• Out of all these medications, only four horses developed synovial sepsis post medication, which is approximately 0.04% of all medications, a very low percentage.
• Two cases each were found to have been given polysulphated glycosaminoglycans and hyaluronate or triamcinolone acetonide and hyaluronate retrospectively. One case had received concurrent medication with amikacin sulphate.
• All four of these cases were able to return to racing after undergoing joint lavage, which is a therapeutic washout of the joint.

Conclusions

• The incidence of synovial sepsis is extremely low in this case population, making multivariable statistical analysis irrelevant. Even though the study was conducted on racing horses in an ambulatory setting, these findings will not likely apply to the general horse population entirely due to differences in care and health conditions.
• However, the risk quantification from this research—0.04% incidence—can inform clients about the potential complications from intrasynovial medication, which can be instrumental in decision-making and achieving informed consent.