title: Synovial membrane microarthroscopy of the equine midcarpal joint.
abstract: 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.
authors.affiliation: Department of Clinical Sciences, College of Veterinary Medicine, Auburn University, Auburn, AL 36849, USA. serenal@auburn.edu
authors.forename: Alberto
authors.initials: A
authors.lastname: Serena
authors.forename: R Reid
authors.initials: RR
authors.lastname: Hanson
authors.forename: Steven A
authors.initials: SA
authors.lastname: Kincaid
mesh_terms: 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