Anthropology, University of Pittsburgh
April 18, 2020 , Platinum Ballroom
The anterior cruciate ligament (ACL) in humans and the cranial cruciate ligament (CCL) in dogs are homologous structures both susceptible to rupture and regularly result in secondary osteoarthritis. Human musculoskeletal problems are the third highest medical cost in the United States with $170 billion spent annually. Women are more susceptible to rupture and it is uncertain why this occurs. Concurrently, different dog breeds exhibit unequal rupture rates, which make them appropriate anatomical models to better understand increased rupture risk factors. This study analyzed data collected from a veterinary hospital comparing CCL ruptured cases (16 females, 13 males) and non-ruptured cases (19 females, 9 males). It used a multicausal approach by looking at tibial plateau angle (TPA), patellar luxation (PL), breed, sex, and reproductively intact status. Among the ruptured cases only 4 of 29 were intact, while 21 of 28 non-ruptured cases were intact (Χ2 = 21.7, p<0.01). However, sex was not statistically significant (Χ2 = 0.97, p>0.01). Overall, these results show large breed, non-intact dogs with abnormal TPAs are more likely to rupture their CCL, suggesting hormonal removal is important in bone and ligament development in dogs. We propose hormonal stop signals in long bones are interrupted and change the bony angle, overextending the ligament and increasing rupture susceptibility. This dog model supports human dimorphic ACL rupture rates as multifactorial and influenced by developmental hormonal variations.