From the American College of Veterinary Surgeons (and you can also search for one on this website) :
https://www.acvs.org/small-animal/cr...gament-disease
Quote from the site:
Rupture of the CCL is one of the most common reasons for hind limb lameness, pain and subsequent arthritis. Since the development of this problem in dogs is much more complex than in humans, and dogs suffer from different degrees of rupture (partial or complete), the condition is referred to as ‘cranial cruciate ligament disease’ (or CCLD). While the degree of lameness with CCLD varies, it invariably causes arthritis in the long-term.