Gentamicin concentrations in synovial fluid obtained from the tarsocrural joints of horses after implantation of gentamicin-impregnated collagen sponges.
OBJECTIVE
To determine synovial fluid gentamicin concentrations and evaluate adverse effects on the synovial membrane and articular cartilage of tarsocrural joints after implantation of a gentamicin-impregnated collagen sponge.


METHODS
6 healthy adult mares.


METHODS
A purified bovine type I collagen sponge impregnated with 130 mg of gentamicin was implanted in the plantarolateral pouch of 1 tarsocrural joint of each horse, with the contralateral joint used as a sham-operated control joint. Gentamicin concentrations in synovial fluid and serum were determined for 120 hours after implantation by use of a fluorescence polarization immunoassay. Synovial membrane and cartilage specimens were collected 120 hours after implantation and evaluated histologically.


RESULTS
Median peak synovial fluid gentamicin concentration of 168.9 microg/mL (range, 115.6 to 332 microg/mL) was achieved 3 hours after implantation. Synovial fluid gentamicin concentrations were < 4 microg/mL by 48 hours. Major histologic differences were not observed in the synovial membrane between control joints and joints implanted with gentamicin-impregnated sponges. Safranin-O fast green stain was not reduced in cartilage specimens obtained from treated joints, compared with those from control joints.


CONCLUSIONS
Implantation of a gentamicin-impregnated collagen sponge in the tarsocrural joint of horses resulted in rapid release of gentamicin, with peak concentrations > 20 times the minimum inhibitory concentration reported for common pathogens that infect horses. A rapid decrease in synovial fluid gentamicin concentrations was detected. The purified bovine type I collagen sponges did not elicit substantial inflammation in the synovial membrane or cause mechanical trauma to the articular cartilage.
Ivester
Kathleen M
KM
Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA.
Adams
Stephen B
SB
Moore
George E
GE
Van Sickle
David C
DC
Lescun
Timothy B
TB
D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D001170:Arthritis, Infectious / Q000188:drug therapy / Q000378:metabolism / Q000662:veterinary*; D002358:Cartilage, Articular / Q000473:pathology; D024042:Collagen Type I / Q000494:pharmacology; D005260:Female; D005839:Gentamicins / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D006651:Histocytochemistry / Q000662:veterinary; D006734:Horse Diseases / Q000097:blood / Q000188:drug therapy / Q000378:metabolism*; D006736:Horses; D018709:Statistics, Nonparametric; D013582:Synovial Fluid / Q000378:metabolism*
D000900:Anti-Bacterial Agents; D024042:Collagen Type I; D005839:Gentamicins