Related Experiment Video
Updated: Jul 17, 2026
Knee Arthrocentesis in Adults
Published on: February 25, 2022
Effect of intrathecal amikacin administration and repeated centesis on digital flexor tendon sheath synovial fluid in
Susanne Dykgraaf1, Julie E Dechant, Jennifer L Johns
1Veterinary Medical Teaching Hospital and the Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis, CA 95616, USA. sdykgraaf@ucdavis.edu
Objective:
To determine the effect of intrathecal amikacin administration and repeated tenovaginocentesis on the total nucleated cell count (TNCC), total protein (TP) concentration and cytologic characteristics of synovial fluid of the equine digital flexor tendon sheath (DFTS).
Study Design:
Randomized, cross-over experimental design.
Animals:
Adult horses (n=8).
Methods:
Synovial fluid was aseptically collected from the DFTS and either 1 mL amikacin sulfate (250 mg/mL) or lactated Ringer's solution (LRS) was injected into the DFTS. Serial synovial fluid samples were obtained at 0, 12, 24, 48, and 72 hours. The opposite treatment was administered to the contralateral DFTS after a washout period of 2 weeks.
Results:
Treatment increased TP concentration, TNCC, percentage of neutrophils, and neutrophil counts from baseline levels. There was no difference between treatment of the DFTS with amikacin or LRS. Values peaked at 12-24 hours after the initial centesis and then declined toward baseline levels.
Conclusions:
Injection and repeat centesis of the normal DFTS with 250 mg amikacin or an equivalent volume of LRS resulted in mild increases in synovial fluid analytes from baseline. Synovial inflammation in this study was not accompanied by lameness at the walk and measured analytes returned toward baseline levels within 12-24 hours of first injection.
Clinical Relevance:
The effect of tenovaginocentesis and intrathecal administration of amikacin or LRS on DFTS synovial fluid values are modest in most horses; however, some horses can develop marked increases in synovial fluid values that may be interpreted as sepsis.
