A variety of surgical procedures are available to ameliorate the discomfort of tendonitis or desmitis, treat the original cause, or enhance healing. The following current techniques are described: neurectomy of the deep penetrating branch of the lateral plantar nerve, suspensory ligament fasciotomy, desmotomy of the palmar/plantar annular ligament via an extrasynovial approach and using arthroscopic guidance, desmotomy of the accessory ligament of the superficial digital flexor tendon (AL-SDFT, proximal check ligament) via the direct medial approach and via arthroscopic guidance, and desmotomy of the accessory ligament of the deep digital flexor tendon (AL-DDFT, distal check ligament).

OBJECTIVE:To evaluate the buffy coat and apheresis methods for preparation of platelet concentrates from equine blood by comparing platelet and growth factor concentrations.ANIMALS:15 mature mixed-breed geldings.PROCEDURE:Whole blood samples were collected and processed by use of a buffy coat or apheresis method to obtain platelet poor and platelet concentrated fractions. The PCV, WBC count, and platelet count were compared among whole blood samples, platelet poor fractions, concentrates obtained by use of the apheresis method (ie, apheresis platelet concentrates), and concentrates obtained by use of the buffy coat method (ie, buffy coat platelet concentrates). Concentrations of transforming growth factor-beta (ie,TGF-beta1 andTGF-beta2) and insulin-like growth factor were compared between buffy coat and apheresis platelet concentrates.RESULTS:Platelet concentrations were 8.9-fold and 5.2-fold greater in buffy coat and apheresis platelet concentrates, respectively, compared with whole blood. Platelet concentrations were 13.1-fold greater in filtered apheresis platelet concentrates, compared with whole blood. TGF-beta1 concentrations were 2.8-fold and 3.1-fold greater in buffy coat and apheresis platelet concentrates, respectively, and TGF-beta1 concentrations were 10.5-fold greater in filtered apheresis platelet concentrates, compared with whole blood. TGF-beta2 concentrations were 3.6-fold greater in apheresis platelet concentrates, compared with whole blood. Platelet concentrations correlated with growth factor concentrations across all blood and platelet fractions. White blood cell counts had a significant positive correlation with TGF-beta1 concentration in buffy coat platelet concentrates.CONCLUSIONS AND CLINICAL RELEVANCE:Platelets and TGF-beta1 can be concentrated reliably from equine blood by use of buffy coat or apheresis methods, without modification of the protocols used for humans.

OBJECTIVE To determine whether iontophoretic administration of dexamethasone to horses results in detectable concentrations in synovial fluid, plasma, and urine. ANIMALS 6 adult mares. PROCEDURE Iontophoresis was used to administer dexamethasone. Treatments (4 mA for 20 minutes) were administered to a tarsocrural joint of each mare. The drug electrode contained 3 ml of dexamethasone sodium phosphate at a concentration of 4 or 10 mg/ml. Samples of synovial fluid, blood, and urine were obtained before and 0.5, 4, 8, and 24 hours after each treatment. All samples were tested for dexamethasone using an ELISA. Synovial fluid also was evaluated for dexamethasone, using high-performance liquid chromatography. RESULTS The lower and upper limits of detection for dexamethasone in synovial fluid with the ELISA were 0.21 and 1.5 ng/ml, respectively. Dexamethasone administered at a concentration of 10 mg/ml was detected by the ELISA in synovial fluid of 5 mares from 0.5 to 24 hours and in urine of 4 mares from 0.5 to 8 hours after each treatment, but it was not detected in plasma. Mean synovial fluid concentration of dexamethasone was 1.01 ng/ml. Dexamethasone administered at a concentration of 4 mg/ml was detected by the ELISA in urine of 2 mares at 0.5 and 4 hours after treatment, but it was not detected in synovial fluid or plasma. CONCLUSIONS AND CLINICAL RELEVANCE Iontophoresis cannot be considered an effective method for delivery of dexamethasone to synovial fluid of horses, because drug concentrations achieved in this study were less than therapeutic concentrations.