Synovial membrane microarthroscopy of the equine midcarpal joint.
OBJECTIVE
To evaluate the value of microarthroscopy in the equine midcarpal joint using the vital stains methylene blue, trypan blue, neutral red, and Janus green B to observe components of the synovial lamina propria, vascular architecture, and synoviocytes.


METHODS
Experimental.


METHODS
Ten horses.


METHODS
Microarthroscopy of left and right midcarpal joints was performed with and without vital staining of the synovium. Four vital stains (methylene blue, trypan blue, neutral red, and Janus green B) were evaluated, with each stain used in 5 joints. Synovial biopsy specimens were collected from the dorsomedial and dorsolateral aspects of the joint.


RESULTS
All dyes were biocompatible. At x 60 without vital staining, synovial surface topography, vascular network, and translucency were observed. Intra-articular vital dyes improved evaluation of synovial surface topography. At x 150 with vital staining, individual synoviocytes were clearly identified with all dyes, except neutral red. Although methylene blue provided the best in vivo microscopic differentiation of the structure of the intima, trypan blue had superior retention in conventionally processed synovial biopsies.


CONCLUSIONS
Methylene blue, trypan blue, neutral red, and Janus green B stains can be used safely for microarthroscopy. Good visualization of cells and vascular network can be obtained by microarthroscopy, and microarthroscopic evaluation of the synovium compares favorably with conventional histologic evaluation of biopsy specimens.


CONCLUSIONS
Microarthroscopy may be beneficial in both research and clinical diagnosis of equine articular diseases.
Serena
Alberto
A
Department of Clinical Sciences, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, USA. serenal@auburn.edu
Hanson
R Reid
RR
Kincaid
Steven A
SA
D000818:Animals; D001182:Arthroscopy / Q000379:methods / Q000662:veterinary*; D002350:Carpus, Animal / Q000166:cytology / Q000601:surgery* / Q000648:ultrastructure; D002358:Cartilage, Articular / Q000166:cytology / Q000601:surgery / Q000648:ultrastructure; D005260:Female; D006651:Histocytochemistry / Q000662:veterinary; D006734:Horse Diseases / Q000175:diagnosis / Q000601:surgery; D006736:Horses / Q000601:surgery*; D008297:Male; D013194:Staining and Labeling / Q000379:methods / Q000662:veterinary*; D000074402:Synovectomy