Discussion

Hawthorn, A.E, Fraser, B.S, O'Meara, B.M, James, F.M, Reardon, R.J.M. and Bladon, B.M.
Aims: To document and investigate the rate of post operative synovial sepsis following elective endoscopic surgery. Methods: The case history of horses that underwent arthroscopy, tenoscopy or bursoscopy at Donnington Grove Veterinary Surgery between January 1999 and January 2012 were examined. Cases with pre- existing synovial sepsis or laceration were excluded, as were horses which did not survive for >14 days and those which underwent arthrotomy. The signalment, anatomical structure involved, use of electrosurgery, tourniquet or motorised resector, the presence of a fracture, whether surgery was performed standing or under general anaesthesia, and the number of structures examined were recorded. Clinical experience had suggested that tendon sheaths, in particular the carpal sheath, were more prone to post operative sepsis so these structures were identified as specific variables. Multivariable logistic regression was used to test the significance of the selected variables. Results: There were 1603 horses that underwent endoscopic surgery of 3037 synovial structures; 2462 joints, 520 tendon sheaths and 55 bursae. There were 15 cases of post operative sepsis, never more than one structure per horse, thus the infection rate was 9/1000 horses or 5/1000 procedures. Sepsis occurred in 7 carpal sheaths, 3 digital flexor sheaths, 3 carpal joints, one fetlock and one stifle joint and in 5 of 161 horses in which electrosurgery was used. Conclusions: Horses undergoing carpal sheath tenoscopy were 10.8 times (95% CI 3.8 - 30.3 P<0.001) more likely to develop sepsis than those undergoing surgery of another synovial structure. Practical significance: The rate of post operative sepsis following endoscopic surgery has not previously been documented. Surgeons should be aware that the carpal sheath is apparently at increased risk of post operative sepsis following endoscopic surgery.