Meniscal Mineralization in Domestic Cats

Objective To (1) determine prevalence of radiographically detectable meniscal mineralization in domestic cats and (2) to evaluate the association between meniscal mineralization and degenerative joint disease (DJD). Study Design Prospective study. Animals Client-owned cats (n=100) and 30 feline cadavers. Methods Randomly selected client-owned cats were used to determine the prevalence of meniscal mineralization. Stifles from feline cadavers were used to evaluate the relationship between meniscal mineralization (using high-resolution X-ray), radiographic DJD, and cartilage damage. Menisci were evaluated histologically. Results Forty-six percent of the client-owned cats had meniscal mineralization detected in 1 or both stifles. Pain scores were not significantly different between stifles with meniscal mineralization and those with no radiographic pathology (P=.38). Thirty-four of 57 cadaver stifles had meniscal mineralization, which was always located in the cranial horn of the medial meniscus. Percentage mineralization of the menisci was significantly correlated with the cartilage damage score of the medial femoral (r2=0.6; P <.0001) and tibial (r2=0.5; P <.0001) condyles as well as with the total joint cartilage damage (r2=0.36; P <.0001) score and DJD score (r2=0.8; P <.0001). Conclusion Meniscal mineralization is a common condition in domestic cats and seems to indicate medial compartment DJD. Clinical Relevance Clinical significance of meniscal mineralization is uncertain. Further work is needed to determine if the meniscal mineralization is a cause, or a consequence of joint degeneration.