Arthroscopic synovitis severity scoring in canine stifles with cranial cruciate ligament disease

To investigate the occurrence, degree, and risk factors associated with arthroscopic stifle joint synovitis in dogs with cranial cruciate ligament (CCL) disease.

Retrospective, observational study.

Canine CCL disease (n = 163) from 149 dogs and their arthroscopic video recordings.

Arthroscopic video recordings were reviewed. A synovitis severity (0-5) and a modified Outerbridge cartilage classification system score were assigned, along with recording the presence or absence of a medial meniscal bucket handle tear. Medical records were reviewed for age, sex, limb, and duration of clinical signs. Univariate analyses were performed via a Fisher's exact test for categorical independent variables, and ordered logistic regression was used for continuous variables. Multivariable ordered logistic regression considered independent variables with a p-value <.2 on univariate analyses. p-value <.05 was considered statistically significant.

Synovitis was identified in 100% of the stifles examined. The most frequent synovitis severity score was 3/5. Univariate analysis showed a significant association between synovitis severity score and bodyweight (p = .005), median cartilage score (p = .002), and being female (p = .032). On multivariable analysis, the synovitis severity score was significantly associated with median cartilage score (p = .042) and duration of clinical signs (p < .001).

Synovitis was arthroscopically always identified in stifles with CCL disease. The severity of synovitis was associated with more progressive damage to the articular cartilage and a longer duration of clinical signs.

Earlier intervention in dogs with CCL disease may be warranted to decrease synovitis and progression of osteoarthritis.