title: Arthroscopic assessment of stifle synovitis in dogs with cranial cruciate ligament rupture.
abstract: Cranial cruciate ligament rupture (CR) is a degenerative condition in dogs that typically has a non-contact mechanism. Subsequent contralateral rupture often develops in dogs with unilateral CR. Synovitis severity is an important factor that promotes ligament degradation. Consequently, we wished to evaluate the utility of arthroscopy for assessment of stifle synovitis in dogs with CR. Herein, we report results of a prospective study of 27 dogs with unilateral CR and bilateral radiographic osteoarthritis. Arthroscopic images and synovial biopsies from the lateral and medial joint pouches were obtained bilaterally and graded for synovial hypertrophy, vascularity, and synovitis. Synovial tartrate-resistant acid phosphatase-positive (TRAP+) macrophages, CD3(+) T lymphocytes, Factor VIII+ blood vessels, and synovial intima thickness were quantified histologically and related to arthroscopic observations. Risk of subsequent contralateral CR was examined using survival analysis. We found that arthroscopic scores were increased in the index stifle, compared with the contralateral stifle (p<0.05). Numbers of CD3+ T lymphocytes (SR = 0.50, p<0.05) and TRAP+ cells in joint pouches (SR = 0.59, p<0.01) were correlated between joint pairs. Arthroscopic grading of vascularity and synovitis was correlated with number density of Factor VIII+ vessels (SR>0.34, p<0.05). Arthroscopic grading of villus hypertrophy correlated with numbers of CD3(+) T lymphocytes (SR = 0.34, p<0.05). Synovial intima thickness was correlated with arthroscopic hypertrophy, vascularity, and synovitis (SR>0.31, p<0.05). Strong intra-observer and moderate inter-observer agreement for arthroscopic scoring was found. Dog age and arthroscopic vascularity significantly influenced risk of contralateral CR over time. We conclude that arthroscopic grading of synovitis is a precise tool that correlates with histologic synovitis. Arthroscopy is useful for assessment of stifle synovitis in client-owned dogs, and could be used in longitudinal clinical trials to monitor synovial responses to disease-modifying therapy.
authors.affiliation: Comparative Orthopaedic Research Laboratory, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.
authors.forename: Jeffrey P
authors.initials: JP
authors.lastname: Little
authors.affiliation: Comparative Orthopaedic Research Laboratory, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.
authors.forename: Jason A
authors.initials: JA
authors.lastname: Bleedorn
authors.affiliation: Comparative Orthopaedic Research Laboratory, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Sutherland
authors.affiliation: Research Animal Resources Center, Comparative Pathology Laboratory, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.
authors.forename: Ruth
authors.initials: R
authors.lastname: Sullivan
authors.affiliation: Comparative Orthopaedic Research Laboratory, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.
authors.forename: Vicki L
authors.initials: VL
authors.lastname: Kalscheur
authors.affiliation: Comparative Orthopaedic Research Laboratory, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.
authors.forename: Megan A
authors.initials: MA
authors.lastname: Ramaker
authors.affiliation: Comparative Orthopaedic Research Laboratory, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.
authors.forename: Susan L
authors.initials: SL
authors.lastname: Schaefer
authors.affiliation: Comparative Orthopaedic Research Laboratory, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.
authors.forename: Zhengling
authors.initials: Z
authors.lastname: Hao
authors.affiliation: Comparative Orthopaedic Research Laboratory, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America.
authors.forename: Peter
authors.initials: P
authors.lastname: Muir
mesh_terms: D000818:Animals; D016118:Anterior Cruciate Ligament / Q000000981:diagnostic imaging / Q000601:surgery*; D000070598:Anterior Cruciate Ligament Injuries; D001182:Arthroscopy; D015415:Biomarkers / Q000097:blood; D004285:Dogs; D005260:Female; D007249:Inflammation / Q000097:blood / Q000473:pathology; D008297:Male; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D011859:Radiography; D012421:Rupture; D013264:Stifle / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*; D016019:Survival Analysis; D013583:Synovial Membrane / Q000000981:diagnostic imaging / Q000473:pathology; D013585:Synovitis / Q000097:blood / Q000000981:diagnostic imaging / Q000601:surgery* / Q000662:veterinary*
chemical_list: D015415:Biomarkers